Patent Publication Number: US-9422039-B2

Title: Suspended marine platform

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of U.S. application Ser. No. 14/007,551, filed Sep. 25, 2013, which is a US national entry of PCT/CA2012/000291 having an international filing date of Mar. 29, 2012, and which claims the benefit of U.S. Provisional Application No. 61/469,514, filed Mar. 30, 2011, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD 
     The present invention relates to a suspended marine platform. More particularly, the present invention relates to a suspended marine platform for use in high-speed watercraft. 
     BACKGROUND 
     High-speed small boats are used in a variety of applications and are particularly useful in military operations, and search and rescue operations. When fast-moving small watercraft encounter even moderately disturbed water, the passengers are subjected to significant forces. At high-speed, in waves of any appreciable size, small watercraft tend to be subjected to rapid and simultaneous vertical and horizontal acceleration and deceleration. 
     When a boat moving at high speed impacts the crest of a wave, the boat tends to simultaneously pitch upwards and decelerate, and when it passes over or through the crest and encounters the trough, the boat tends to pitch downwards and accelerate. At high speed, each pitching and acceleration/deceleration cycle may be measured in seconds, such that passengers are subjected to rapid and extreme acceleration and deceleration and the associated shock, which is commonly quantified in terms of multiples of g, a “g” being a unit of acceleration equivalent to that exerted by the earth&#39;s gravitational field at the surface of the earth. The term g-force is also often used, but it is commonly understood to mean a relatively long-term acceleration. A short-term acceleration is usually called a shock and is also quantified in terms of g. 
     Human tolerances for shock and g-force depend on the magnitude of the acceleration, the length of time it is applied, the direction in which it acts, the location of application, and the posture of the body. When vibration is experienced, relatively low peak g levels can be severely damaging if they are at the resonance frequency of organs and connective tissues. In high-speed watercraft, with the passengers sitting in a conventional generally upright position, which is typically required, particularly with respect to the helmsperson and any others charged with watchkeeping, upward acceleration of the watercraft is experienced as a compressive force to an individual&#39;s spine and rapid deceleration tends to throw an individual forward. 
     Shock absorbing systems for high-speed boats are known. For example, U.S. Pat. No. 6,786,172 (Loffler—Shock absorbing boat) discloses a horizontal base for supporting a steering station that that is hingedly connected to the transom to pivot about a horizontal axis. The base is supported by spring bias means connected to the hull. 
     Impact attenuation systems for aircraft seats are also known, as disclosed in: U.S. Pat. No. 4,349,167 (Reilly—Crash load attenuating passenger seat); U.S. Pat. No. 4,523,730 (Martin—Energy-absorbing seat arrangement); U.S. Pat. No. 4,911,381 (Cannon et al.—Energy absorbing leg assembly for aircraft passenger seats); U.S. Pat. No. 5,125,598 (Fox—Pivoting energy attenuating seat); and U.S. Pat. No. 5,152,578 Kiguchi—Leg structure of seat for absorbing impact energy. 
     Other seat suspension systems are also known, as disclosed in: U.S. Pat. No. 5,657,950 (Han et al.—Backward-leaning-movement seat leg structure); U.S. patent application Ser. No. 10/907,931 (App.) (Barackman et al.—Adjustable attenuation system for a space re-entry vehicle seat); U.S. Pat. No. 3,572,828 (Lehner—Seat for vehicle preferably agricultural vehicle); U.S. Pat. No. 3,994,469 (Swenson et al.—Seat suspension including improved damping means); and U.S. Pat. No. 4,047,759 (Koscinski—Compact seat suspension for lift truck). 
     SUMMARY 
     In one aspect, the present invention provides a suspension system for a suspended marine platform on a high-speed water vessel having a usual direction of travel, the suspension system including: a shock absorbing assembly for resiliently suspending a marine platform relative to a vessel, wherein the shock absorbing assembly tends to cause the marine platform to remain in an upper at-rest position and to return to the at-rest position on cessation of a force causing the marine platform to move generally vertically towards a bottom position; two spar assemblies, one spar assembly forward of the other spar assembly, and each spar assembly comprising a first spar and a second spar, each spar pivotally attached at a proximal end to the vessel and at a distal end to the marine platform, wherein: the proximal ends are aft of the distal ends; and the proximal ends of the spars are spaced athwart one from the other a greater distance than the distal ends of the spars are spaced athwart one from the other; wherein one spar assembly is forward of the other spar assembly; and wherein: the attachment of one spar assembly to the vessel permits relative fore and aft movement as between the spar and the vessel; or the attachment of one spar assembly to the marine platform permits relative fore and aft movement as between the spar and the marine platform. 
     The attachment of the one spar assembly to the marine platform preferably permits relative fore and aft movement as between the spar and the marine platform. 
     The relative fore and aft movement as between the spar and the marine platform may be linear. The relative fore and aft movement as between the spar and the marine platform may be provided by a track and car assembly. 
     The relative fore and aft movement as between the spar and the marine platform may be arcuate. The relative fore and aft movement as between the spar and the marine platform may be provided by a pivot assembly. 
     The suspension system may include a roll-attenuation assembly interconnected between the marine platform and the vessel. The roll-attenuation assembly including a torsion bar mounted so as to extend athwart, the torsion bar comprising a torsion spring having at each end an arm extending laterally from the torsion spring, wherein the torsion spring is mounted to one of the marine platform and the vessel, and the arms are each interconnected to the other of the marine platform and the vessel. 
     In one of the spar assemblies, the first spar and second spar may be fixed one to the other in the vicinity of their distal ends and share a common pivotal attachment to the marine platform. 
     The shock absorbing assembly may include four shock-absorbing struts interconnected between the marine platform and the vessel. 
     In another aspect, the present invention provides a suspension system for a suspended marine platform on a high-speed water vessel having a usual direction of travel, the suspension system comprising: a shock absorbing assembly for resiliently suspending a marine platform relative to a vessel, wherein the shock absorbing assembly tends to cause the marine platform to remain in an upper at-rest position and to return to the at-rest position on cessation of a force causing the marine platform to move generally vertically towards a bottom position; two spar assemblies, one spar assembly forward of the other spar assembly, and each spar assembly comprising a first spar and a second spar, each spar pivotally attached at a proximal end to the vessel and at a distal end to the marine platform, wherein: the proximal ends are aft of the distal ends; and the proximal ends of the spars are spaced athwart one from the other a greater distance than the distal ends of the spars are spaced athwart one from the other; wherein one spar assembly is forward of the other spar assembly; wherein the attachment of one spar assembly to the marine platform comprises a track and car assembly so as to permit relative linear fore and aft movement as between the spar and the marine platform; and further comprising a roll-attenuation assembly interconnected between the marine platform and the vessel. 
     The roll-attenuation assembly may include a torsion bar mounted so as to extend athwart, the torsion bar comprising a torsion spring having at each end an arm extending laterally from the torsion spring, wherein the torsion spring is mounted to one of the marine platform and the vessel, and the arms are each interconnected to the other of the marine platform and the vessel. The shock absorbing assembly may include four shock-absorbing struts interconnected between the marine platform and the vessel. 
     In another aspect, the present invention includes a suspension system for a suspended marine platform on a high-speed water vessel having a usual direction of travel, the suspension system including: a shock absorbing assembly for resiliently suspending a marine platform relative to a vessel, wherein the shock absorbing assembly tends to cause the marine platform to remain in an upper at-rest position and to return to the at-rest position on cessation of a force causing the marine platform to move generally vertically towards a bottom position; two spar assemblies, one spar assembly forward of the other spar assembly, and each spar assembly comprising a first spar and a second spar, each spar pivotally attached at a proximal end to the vessel and at a distal end to the marine platform, wherein: the proximal ends are aft of the distal ends; and the proximal ends of the spars are spaced athwart one from the other a greater distance than the distal ends of the spars are spaced athwart one from the other; wherein one spar assembly is forward of the other spar assembly; wherein the attachment of one spar assembly to the marine platform comprises a pivot assembly so as to permit relative arcuate fore and aft movement as between the spar and the marine platform; and further comprising a roll-attenuation assembly interconnected between the marine platform and the vessel. 
     The roll-attenuation assembly may include a torsion bar mounted so as to extend athwart, the torsion bar comprising a torsion spring having at each end an arm extending laterally from the torsion spring, wherein the torsion spring is mounted to one of the marine platform and the vessel, and the arms are each interconnected to the other of the marine platform and the vessel. The shock absorbing assembly may include four shock-absorbing struts interconnected between the marine platform and the vessel. 
    
    
     
       SUMMARY OF THE DRAWINGS 
         FIG. 1  is a forward-port-side isometric partially transparent view of a double-wishbone anti-sway embodiment of the present invention, shown in the at-rest position. 
         FIG. 2  is a starboard-side elevation view of the embodiment illustrated in  FIG. 1 , shown in the at-rest position. 
         FIG. 3  is a forward elevation view of the embodiment illustrated in  FIG. 1 , shown in the at-rest position. 
         FIG. 4  is a bottom plan view of the embodiment illustrated in  FIG. 1 , shown in the at-rest position. 
         FIG. 5  is a starboard-side elevation view of the embodiment illustrated in  FIG. 1 , shown in a compressed position. 
         FIG. 6  is a forward elevation view of the embodiment illustrated in  FIG. 1 , shown in a compressed position. 
         FIG. 7  is a starboard-side elevation view of the embodiment illustrated in  FIG. 1 , shown in a rolled-to-starboard position. 
         FIG. 8  is a forward elevation view of the embodiment illustrated in  FIG. 1 , shown in a rolled-to-starboard position. 
         FIG. 9  is a forward-port-side isometric partially transparent view of a single-wishbone panhard anti-sway embodiment of the present invention, shown in the at-rest position. 
         FIG. 10  is a starboard-side elevation view of the embodiment illustrated in  FIG. 9 , shown in the at-rest position. 
         FIG. 11  is a forward elevation view of the embodiment illustrated in  FIG. 9 , shown in the at-rest position. 
         FIG. 12  is a bottom plan view of the embodiment illustrated in  FIG. 9 , shown in the at-rest position. 
         FIG. 13  is a starboard-side elevation view of the embodiment illustrated in  FIG. 9 , shown in a compressed position. 
         FIG. 14  is a forward elevation view of the embodiment illustrated in  FIG. 9 , shown in a compressed position. 
         FIG. 15  is a bottom plan view of the embodiment illustrated in  FIG. 9 , shown in a compressed position. 
         FIG. 16  is a starboard-side elevation view of the embodiment illustrated in  FIG. 9 , shown in a rolled-to-port position. 
         FIG. 17  is a forward elevation view of the embodiment illustrated in  FIG. 9 , shown in a rolled-to-port position. 
         FIG. 18  is a rear-port-side isometric view of a control-module double-wishbone embodiment of the present invention, shown in the at-rest position. 
         FIG. 19  is a forward-port-side isometric partially transparent view of a single-wishbone Watt&#39;s linkage anti-sway embodiment of the present invention, shown in the at-rest position. 
         FIG. 20  is a starboard-side elevation view of the embodiment illustrated in  FIG. 19 , shown in the at-rest position. 
         FIG. 21  is a forward elevation view of the embodiment illustrated in  FIG. 19 , shown in the at-rest position. 
         FIG. 22  is a bottom plan view of the embodiment illustrated in  FIG. 19 , shown in the at-rest position. 
         FIG. 23  is a starboard-side elevation view of the embodiment illustrated in  FIG. 19 , shown in a compressed position. 
         FIG. 24  is a forward elevation view of the embodiment illustrated in  FIG. 19 , shown in a compressed position. 
         FIG. 25  is a bottom plan view of the embodiment illustrated in  FIG. 19 , shown in a compressed position. 
         FIG. 26  is a starboard-side elevation view of the embodiment illustrated in  FIG. 19 , shown in a rolled-to-starboard position. 
         FIG. 27  is a forward elevation view of the embodiment illustrated in  FIG. 19 , shown in a rolled-to-starboard position. 
         FIG. 28  is a forward-port-side isometric partially transparent view of a double two-spar roll-attenuation embodiment of the present invention, shown in the at-rest position. 
         FIG. 29  is a starboard-side elevation view of the embodiment illustrated in  FIG. 28 , shown in the at-rest position. 
         FIG. 30  is a forward elevation view of the embodiment illustrated in  FIG. 28 , shown in the at-rest position. 
         FIG. 31  is a bottom plan view of the embodiment illustrated in  FIG. 28 , shown in the at-rest position. 
         FIG. 32  is a starboard-side elevation view of the embodiment illustrated in  FIG. 28 , shown in a compressed position. 
         FIG. 33  is a forward elevation view of the embodiment illustrated in  FIG. 28 , shown in a compressed position. 
         FIG. 34  is a starboard-side elevation view of the embodiment illustrated in  FIG. 28 , shown in a rolled-to-starboard position. 
         FIG. 35  is a forward elevation view of the embodiment illustrated in  FIG. 28 , shown in a rolled-to-starboard position. 
         FIG. 36  is a forward-port-side isometric partially transparent view of a single two-spar panhard roll-attenuation embodiment of the present invention, shown in the at-rest position. 
         FIG. 37  is a starboard-side elevation view of the embodiment illustrated in  FIG. 36 , shown in the at-rest position. 
         FIG. 38  is a forward elevation view of the embodiment illustrated in  FIG. 36 , shown in the at-rest position. 
         FIG. 39  is a bottom plan view of the embodiment illustrated in  FIG. 36 , shown in the at-rest position. 
         FIG. 40  is a starboard-side elevation view of the embodiment illustrated in  FIG. 36 , shown in a compressed position. 
         FIG. 41  is a forward elevation view of the embodiment illustrated in  FIG. 36 , shown in a compressed position. 
         FIG. 42  is a bottom plan view of the embodiment illustrated in  FIG. 36 , shown in a compressed position. 
         FIG. 43  is a starboard-side elevation view of the embodiment illustrated in  FIG. 36 , shown in a rolled-to-starboard position. 
         FIG. 44  is a forward elevation view of the embodiment illustrated in  FIG. 36 , shown in a rolled-to-starboard position. 
         FIG. 45  is a forward-port-side isometric partially transparent view of a single two-spar Watt&#39;s linkage roll-attenuation pitch-attenuation embodiment of the present invention, shown in the at-rest position. 
         FIG. 46  is a starboard-side elevation view of the embodiment illustrated in  FIG. 45 , shown in the at-rest position. 
         FIG. 47  is a forward elevation view of the embodiment illustrated in  FIG. 45 , shown in the at-rest position. 
         FIG. 48  is a bottom plan view of the embodiment illustrated in  FIG. 45 , shown in the at-rest position. 
         FIG. 49  is a starboard-side elevation view of the embodiment illustrated in  FIG. 45 , shown in a compressed position. 
         FIG. 50  is a forward elevation view of the embodiment illustrated in  FIG. 45 , shown in a compressed position. 
         FIG. 51  is a bottom plan view of the embodiment illustrated in  FIG. 45 , shown in a compressed position. 
         FIG. 52  is a starboard-side elevation view of the embodiment illustrated in  FIG. 45 , shown in a rolled-to-starboard position. 
         FIG. 53  is a forward elevation view of the embodiment illustrated in  FIG. 45 , shown in a rolled-to-starboard position. 
         FIG. 54  is a forward-port-side isometric partially transparent view of a single one-spar-two-spar roll-attenuation pitch-attenuation embodiment of the present invention, shown in the at-rest position. 
         FIG. 55  is a starboard-side elevation view of the embodiment illustrated in  FIG. 54 , shown in the at-rest position. 
         FIG. 56  is a forward elevation view of the embodiment illustrated in  FIG. 54 , shown in the at-rest position. 
         FIG. 57  is a starboard-side elevation view of the embodiment illustrated in  FIG. 54 , shown in a compressed position. 
         FIG. 58  is a bottom plan view of the embodiment illustrated in  FIG. 54 , shown in a compressed position. 
         FIG. 59  is a starboard-side elevation view of the embodiment illustrated in  FIG. 54 , shown in a rolled-to-port position. 
         FIG. 60  is a forward elevation view of the embodiment illustrated in  FIG. 54 , shown in a rolled-to-port position. 
         FIG. 61  is a forward-port-side isometric partially transparent view of a single two-spar-two-spar roll-attenuation pitch-attenuation embodiment of the present invention, shown in the at-rest position. 
         FIG. 62  is a starboard-side elevation view of the embodiment illustrated in  FIG. 61 , shown in the at-rest position. 
         FIG. 63  is a forward elevation view of the embodiment illustrated in  FIG. 61 , shown in the at-rest position. 
         FIG. 64  is a starboard-side elevation view of the embodiment illustrated in  FIG. 61 , shown in a compressed position. 
         FIG. 65  is a bottom plan view of the embodiment illustrated in  FIG. 61 , shown in a compressed position. 
         FIG. 66  is a starboard-side elevation view of the embodiment illustrated in  FIG. 61 , shown in a rolled-to-port position. 
         FIG. 67  is a forward elevation view of the embodiment illustrated in  FIG. 61 , shown in a rolled-to-port position. 
         FIG. 68  is a forward-port-side isometric partially transparent view of a single three-spar anti-sway anti-pitch clevis-mount embodiment of the present invention, shown in the at-rest position. 
         FIG. 69  is a starboard-side elevation view of the embodiment illustrated in  FIG. 68 , shown in the at-rest position. 
         FIG. 70  is a forward elevation view of the embodiment illustrated in  FIG. 68 , shown in the at-rest position. 
         FIG. 71  is a starboard-side elevation view of the embodiment illustrated in  FIG. 68 , shown in a compressed position. 
         FIG. 72  is a bottom plan view of the embodiment illustrated in  FIG. 68 , shown in a compressed position. 
         FIG. 73  is a starboard-side elevation view of the embodiment illustrated in  FIG. 68 , shown in a rolled-to-port position. 
         FIG. 74  is a forward elevation view of the embodiment illustrated in  FIG. 68 , shown in a rolled-to-port position. 
         FIG. 75  is a forward-port-side isometric partially transparent view of a single three-spar roll-attenuation pitch-attenuation embodiment of the present invention, shown in the at-rest position. 
         FIG. 76  is a starboard-side elevation view of the embodiment illustrated in  FIG. 75 , shown in the at-rest position. 
         FIG. 77  is a forward elevation view of the embodiment illustrated in  FIG. 75 , shown in the at-rest position. 
         FIG. 78  is a starboard-side elevation view of the embodiment illustrated in  FIG. 75 , shown in a compressed position. 
         FIG. 79  is a bottom plan view of the embodiment illustrated in  FIG. 75 , shown in a compressed position. 
         FIG. 80  is a starboard-side elevation view of the embodiment illustrated in  FIG. 75 , shown in a rolled-to-starboard position. 
         FIG. 81  is a forward elevation view of the embodiment illustrated in  FIG. 75 , shown in a rolled-to-starboard position. 
         FIG. 82  is a forward-port-side isometric partially transparent view of a single three-spar Z-style roll-attenuation pitch-attenuation embodiment of the present invention, shown in the at-rest position. 
         FIG. 83  is a starboard-side elevation view of the embodiment illustrated in  FIG. 82 , shown in the at-rest position. 
         FIG. 84  is a forward elevation view of the embodiment illustrated in  FIG. 82 , shown in the at-rest position. 
         FIG. 85  is a starboard-side elevation view of the embodiment illustrated in  FIG. 82 , shown in a compressed position. 
         FIG. 86  is a bottom plan view of the embodiment illustrated in  FIG. 82 , shown in a compressed position. 
         FIG. 87  is a starboard-side elevation view of the embodiment illustrated in  FIG. 82 , shown in a rolled-to-starboard position. 
         FIG. 88  is a forward elevation view of the embodiment illustrated in  FIG. 82 , shown in a rolled-to-starboard position. 
         FIG. 89  is a forward-port-side isometric partially transparent view of a single three-spar Z-style roll-attenuation pitch-attenuation clevis-mount embodiment of the present invention, shown in the at-rest position. 
         FIG. 90  is a starboard-side elevation view of the embodiment illustrated in  FIG. 89 , shown in the at-rest position. 
         FIG. 91  is a forward elevation view of the embodiment illustrated in  FIG. 89 , shown in the at-rest position. 
         FIG. 92  is a starboard-side elevation view of the embodiment illustrated in  FIG. 89 , shown in a compressed position. 
         FIG. 93  is a bottom plan view of the embodiment illustrated in  FIG. 89 , shown in a compressed position. 
         FIG. 94  is a starboard-side elevation view of the embodiment illustrated in  FIG. 89 , shown in a rolled-to-starboard position. 
         FIG. 95  is a forward elevation view of the embodiment illustrated in  FIG. 89 , shown in a rolled-to-starboard position. 
         FIG. 96  is an isometric isolation view of a portion of an anti-sway assembly embodiment of the present invention. 
         FIG. 97  is an isometric isolation view of an in-line clevis mount embodiment of the present invention. 
         FIG. 98  is a bottom plan view of a laterally displaced clevis mount embodiment of the present invention. 
         FIG. 99  is a perspective from-below isolation view of a sliding spar bracket embodiment. 
         FIG. 100  is a perspective from-below isolation view of the sliding spar bracket embodiment of  FIG. 99 , shown with spars. 
         FIG. 101  is a perspective from-below isolation view of a sliding spar bracket with track mount embodiment. 
         FIG. 102  is a perspective from-below isolation view of the sliding spar bracket with track mount embodiment of  FIG. 101 , shown with spars. 
         FIG. 103  is a perspective exploded view of a pivot block and pivot pin assembly embodiment. 
         FIG. 104  is a cutaway perspective view of a pivoting spar bracket embodiment, shown with spars. 
         FIG. 105  is a perspective from-below view of a double two-spar roll-attenuation embodiment of the present invention with movement-accommodating spar brackets wherein the forward spars are interconnected to the marine platform via a sliding spar bracket and the torsion spring is attached to the marine platform roughly in the middle of the fore and aft extent of the marine platform and with the adjustable torsion arms extending aft from the torsion spring. 
         FIG. 106  is a side elevation view of embodiment shown in  FIG. 105 . 
         FIG. 107  is a perspective from-below view of a double two-spar roll-attenuation embodiment of the present invention with movement-accommodating spar brackets wherein the aft spars are interconnected to the marine platform via a sliding spar bracket and the torsion spring is attached to the marine platform toward the forward end of the marine platform and with the adjustable torsion arms extending forward from the torsion spring. 
         FIG. 108  is a side elevation view of embodiment shown in  FIG. 107 . 
         FIG. 109  is a perspective from-below view of a double two-spar roll-attenuation embodiment of the present invention with movement-accommodating spar brackets wherein the aft spars are interconnected to the marine platform via a pivoting spar bracket and the torsion spring is attached to the marine platform toward the forward end of the marine platform and with the adjustable torsion arms extending forward from the torsion spring. 
         FIG. 110  is a side elevation view of embodiment shown in  FIG. 109 . 
     
    
    
     DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS 
     In this specification, including the claims, terms conveying an absolute direction (for example, up, down etc.) or absolute relative positions (for example, top, bottom etc.) are used for clarity of description and it is understood that such absolute directions and relative positions may not always pertain. As well, in this specification, including the claims, terms relating to directions and relative orientations on a watercraft, for example, port, starboard, forward, aft, fore and aft (which when used herein means a generally horizontal direction generally parallel to the direction of travel of the vessel), bow, stern, athwart (which when used herein means a generally horizontal direction generally perpendicular to the direction of travel of the vessel) etc. are used for clarity of description and it is understood that such terms may not always pertain. 
     As well, in this specification, including the claims, the terms “roll and “pitch” are used to refer to movement relative to an imaginary line parallel to the nominal direction of travel of the vessel or object, and passing through the center of mass of the vessel or object, with “roll” being quasi-pivotal or quasi-rotational lateral movement with respect to the imaginary line, and “pitch” being a generally vertical angle of displacement (e.g. bow up or bow down) caused by a vertical force applied at a distance from the center of mass. 
     In most of the figures, a marine platform  200  is represented in a simplified stylized manner, however it will be appreciated that in an actual installation, marine platform  200  may comprise several other features, including: contoured seats, windscreens, covers, vessel controls etc. As well, marine platform  200  may be a passenger module comprising a plurality of individual seats. Marine platform  200  may be configured for use with a variety of items, including a stretcher or stretchers, cargo, a cockpit, a pallet of seats, and may configured for interchangeable use with many different types of such items. 
     In the figures, a deck  204  is indicated as being below, and providing support for, the marine platform  200 . In an actual installation, the marine platform  200  and the associated suspension system are typically mounted to the vessel, such as to an integral deck. However, in some installations, it may be preferable to mount the marine platform  200  and suspension system to a carriage (such as a suitable plate or framework) and to attach the carriage to the vessel. 
     The embodiments shown in the figures all have four shock absorbing struts  206 , which serve to suspend marine platform  200  above deck  204 , with each strut  206  shown as positioned in the general vicinity of an associated corner of the marine platform  200  and extending generally vertically. In the figures, each strut  206  is secured to deck  204  with a strut deck bracket  207  and to marine platform  200  with a strut module bracket  208 . The struts  206  may be any suitable type of shock absorber such as air shocks, MacPherson struts etc. Further, there need not be exactly four struts  206 ; more or fewer struts  206  may be suitable in some applications. 
     Some of the embodiments shown in the drawings include a roll-attenuation assembly  220  and/or a pitch-attenuation assembly  230 . The roll-attenuation assembly  220  and the pitch-attenuation assembly  230  share functionally analogous components and for convenience and simplicity herein such functionally analogous components are given the same descriptive terms and reference numbers, though it will be understood that such components may differ in many respects, including size, as between the roll-attenuation assembly  220  and the pitch-attenuation assembly  230 . 
     Each of the roll-attenuation assembly  220  and the pitch-attenuation assembly  230  includes a torsion bar  240 , comprising: a longitudinally extending torsion spring  242  having at each end a torsion arm  244  or an adjustable torsion arm  246 , extending laterally from the torsion spring  242 . The torsion arm  244  has a torsion arm mounting hole  247  in the vicinity of the end of the torsion arm  244  opposite the torsion spring  242 . The adjustable torsion arm  246  has a plurality of torsion arm mounting holes  247  in the vicinity of the end of the adjustable torsion arm  246  opposite the torsion spring  242 . 
     A torsion arm link  248  or adjustable torsion arm link  250  is pivotally connected to each of the torsion arm  244  and adjustable torsion arm  246  at a respective torsion arm mounting hole  247 . At the end of each torsion arm link  248  or adjustable torsion arm link  250  opposite the connection to the torsion arm  244  or adjustable torsion arm  246 , as the case may be, there is a link bracket  252 , that in use is mounted to the marine platform  200  or deck  204  or other appropriate component. 
     Along the torsion spring  242 , there are two torsion-bar mounts  254  for mounting the torsion bar  240  to the marine platform  200  or deck  204  or other appropriate component. The torsion-bar mounts  254  tend to impede longitudinal movement of the torsion spring  242  while permitting rotational movement of the torsion spring  242 . 
     In use, the roll-attenuation assembly  220  is mounted with the relevant torsion spring  242  extending athwart. In use, the pitch-attenuation assembly  230  is mounted with the relevant torsion spring  242  extending fore and aft. 
     The roll-attenuation assembly  220  and pitch-attenuation assembly  230  function along the lines of a conventional anti-sway bar in that the roll-attenuation assembly  220  and pitch-attenuation assembly  230  impede differential relative vertical movement between the two sets of components between which the two ends of the roll-attenuation assembly  220  and pitch-attenuation assembly  230  are interconnected. The degree to which the roll-attenuation assembly  220  and pitch-attenuation assembly  230  impede such relative vertical movement (i.e., the “stiffness” of the roll-attenuation assembly  220  and pitch-attenuation assembly  230 ) depends on the size and characteristics of the torsion spring  242 ; and the distance between the axis of rotation of the torsion spring  242  and the connection between the torsion arm  244  or adjustable torsion arm  246  and the torsion arm link  248  or adjustable torsion arm link  250  (as the case may be). Therefore, the “stiffness” of the roll-attenuation assembly  220  and pitch-attenuation assembly  230  may be adjusted by changing the torsion spring  242 , and by moving the location of the connection between the adjustable torsion arm  246  and the torsion arm link  248  or adjustable torsion arm link  250  (as the case may be) by moving the connection to a different one of the plurality of torsion arm mounting holes  247  provided in the adjustable torsion arm  246 . 
     The adjustable torsion arm  246  includes a bottlescrew  260  so as to permit adjustment of the length of the adjustable torsion arm  246 . 
     Some of the embodiments shown in the drawings include spars  270 , pivotally connected between the marine platform  200  and deck  204 , by way of spar brackets  272 , spar clevis brackets  274  or spar clevis lateral brackets  276 . 
     In this specification, the term wishbone (e.g., forward wishbone  302  and aft wishbone  304 ) is used to refer to an assembly of two spars in which the two spars are fixed one to the other in the vicinity of the marine platform  200  and share a common pivotal attachment to the marine platform  200 , being a wishbone platform bracket  312 . 
     The spars  270  preferably have heim joints  314  (also referred to as rod end bearings and rose joints) at each end. The forward wishbone  302  and aft wishbone  304  preferably have heim joints  314  for the connection to the wishbone platform bracket  312 . The heim joints  314  are preferably high-strength stainless steel heim joints. 
     Referring to  FIGS. 1 through 8 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated double-wishbone roll-attenuation suspension system, generally referenced by numeral  300 , mounted to a deck  204 . In  FIGS. 1 through 4 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 5 and 6 , the embodiment is shown with the marine platform  200  in a compressed bottom position In  FIGS. 7 and 8 , the embodiment is shown with the marine platform  200  rolled to starboard relative to the deck  204 . 
     In the embodiment shown in  FIGS. 1 through 8 , the double-wishbone roll-attenuation suspension system  300 , includes four struts  206 , a forward wishbone  302 , an aft wishbone  304 , and a roll-attenuation assembly  220 . 
     As shown in the figures, each of the forward wishbone  302  and aft wishbone  304  is pivotally attached to the deck  204  with two wishbone deck brackets  310  and is pivotally attached to the marine platform  200  with a wishbone platform bracket  312 . The heim joint  314  at the connection between each wishbone platform bracket  312  and the respective forward wishbone  302  and aft wishbone  304  permits some lateral pivotal movement so as to accommodate rolling of the marine platform  200  relative to the deck  204  when in use. 
     In use, fast-moving relatively small watercraft are subject to complicated threes that cause the vessels to pitch, yaw, roll, rise, fait, decelerate and accelerate. The response of the double-wishbone anti-sway suspension system  210  embodiment to such forces is indicated in  FIGS. 5 through 8 . 
     Referring to  FIGS. 9 through 17 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated single-wishbone panhard roll-attenuation suspension system, generally referenced by numeral  350 , mounted to a deck  204 . In  FIGS. 9 through 12 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 13 through 15 , the embodiment is shown with the marine platform  200  in a compressed bottom position. In  FIGS. 16 and 17 , the embodiment is shown with the marine platform  200  rotted to port relative to the deck  204 . 
     In the embodiment shown in  FIGS. 9 through 17 , the single-wishbone panhard roll-attenuation suspension system  350 , includes four struts  206 , an aft wishbone  304 , a roll-attenuation assembly  220  and a panhard assembly  360 . The aft wishbone  214  is configured and mounted as described above. 
     The panhard assembly  360  comprises a panhard rod  362 , a panhard deck mount  364  and a panhard platform mount  366 . The proximal end of the panhard rod  362  is pivotally mounted to the deck  204  with the panhard deck mount  364 . The distal end of the panhard rod  362  is pivotally mounted to the marine platform  200  with the panhard platform mount  366 . 
     In the embodiment shown in  FIGS. 9 through 17 , the panhard assembly  360  is positioned in the vicinity of the forward end of marine platform  200 . The panhard assembly  360  prevents more than minimal lateral movement of marine platform  200  relative to deck  204 . As the distal end of panhard rod  362  moves in an arc as marine platform  200  moves vertically relative to the deck  204 , panhard rod  360  induces a slight lateral movement of marine platform  200  during vertical movement of marine platform  200 . This slight lateral movement of marine platform  200  relative to deck  204  is accommodated generally by the various connections between the components of embodiment being configured to permit some relative lateral movement. 
     Referring to  FIG. 18 , there is illustrated an embodiment of the present invention comprising a control module  400 , and a double-wishbone suspension system, generally referenced by numeral  410 , mounted to a deck  204 . 
     The control module  400  comprises two seats  420 , a helm/control station  422 , two foot rests  424  (one on the port side and the other on the starboard side; only one is visible in the drawing) and two foot openings  426  (again, one on the port side and the other on the starboard side; only one is visible in the drawing). The foot openings  426  permit users to selectively stand on the deck  204  or sit on the seats  420  while controlling the vessel or while being partially sheltered from spray by the control module  400 . 
     In the embodiment shown in  FIG. 18 , the double-wishbone suspension system  410 , includes four struts  206 , a forward wishbone  302  and an aft wishbone  304 . 
     Referring to  FIGS. 19 through 27 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated single-wishbone Watt&#39;s linkage roll-attenuation suspension system, generally referenced by numeral  450 , mounted to a deck  204 . In  FIGS. 19 through 22 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 23 through 25 , the embodiment is shown with the marine platform  200  in a compressed bottom position. In  FIGS. 26 and 27 , the embodiment is shown with the marine platform  200  rolled to starboard relative to the deck  204 . 
     In the embodiment shown in  FIGS. 19 through 27 , the single-wishbone Watt&#39;s linkage roll-attenuation suspension system  450 , includes four struts  206 , an aft wishbone  214 , a roll-attenuation assembly  222  and a Watt&#39;s linkage  460 . 
     The Watt&#39;s linkage  460  embodiment shown in the drawings comprises a Watt&#39;s link  462  rotatably mounted to the marine platform  200 ; a starboard Watt&#39;s rod  464  attached at one end to the Wads link  462  and attached at the other end to the deck  204  via a starboard Watt&#39;s rod deck mount  466 ; and a port Watts rod  468  attached at one end to the Wads link  462  (opposite the location of attachment of the starboard Watt&#39;s rod  464 ) and attached at the other end to the deck  204  via a port Watt&#39;s rod deck mount  470 . 
     The Watt&#39;s linkage  460  permits vertical movement of the marine platform  200  relative to the deck  204 , with minimal lateral movement of the marine platform  200  relative to the deck  204 . 
     Referring to  FIGS. 28 through 35 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated double two-spar roll-attenuation suspension system, generally referenced by numeral  500 , mounted to a deck  204 . In  FIGS. 28 through 31 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 32 and 33 , the embodiment is shown with the marine platform  200  in a compressed bottom position. In  FIGS. 34 and 35 , the embodiment is shown with the marine platform  200  rolled to starboard relative to the deck  204 . 
     In the embodiment shown in  FIGS. 28 through 35 , the double two-spar roll-attenuation suspension system  500 , includes four struts  206 , a roll-attenuation assembly  220  and four spars  270 . The spars  270  are arranged in two pairs, a forward pair and an aft pair, with each pair in the shape of a V, with the base of the V attached to the marine platform  200  and the top of the V attached to the deck  204 . 
     Referring to  FIGS. 36 through 44 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated single two-spar panhard roll-attenuation suspension system, generally referenced by numeral  550 , mounted to a deck  204 . In  FIGS. 36 through 39 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 40 through 42 , the embodiment is shown with the marine platform  200  in a compressed bottom position. In  FIGS. 43 and 44 , the embodiment is shown with the marine platform  200  rolled to port relative to the deck  204 . 
     In the embodiment shown in  FIGS. 36 through 44 , the single two-spar panhard roll-attenuation suspension system  550 , includes four struts  206 , a roll-attenuation assembly  220 , a panhard assembly  360  and two spars  270 . The spars  270  are arranged as a single aft pair, with the pair in the shape of a V, with the base of the V attached to the marine platform  200  and the top of the V attached to the deck  204 . 
     Referring to  FIGS. 45 through 53 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated single two-spar Watt&#39;s linkage roll-attenuation pitch-attenuation suspension system, generally referenced by numeral  600 , mounted to a deck  204 . In  FIGS. 45 through 48 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 49 through 51 , the embodiment is shown with the marine platform  200  in a compressed bottom position. In  FIGS. 52 and 53 , the embodiment is shown with the marine platform  200  rolled to starboard relative to the deck  204 . 
     In the embodiment shown in  FIGS. 45 through 53 , the single two-spar Watt&#39;s linkage roll-attenuation pitch-attenuation suspension system  600 , includes four struts  206 , a roll-attenuation assembly  220 , a pitch-attenuation assembly  230 , a Watt&#39;s linkage  460  and two spars  270 . The spars  270  are arranged as a single aft pair, with the pair in the shape of a V, with the base of the V attached to the marine platform  200  and the top of the V attached to the deck  204 . 
     Referring to  FIGS. 54 through 60 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated single one-spar-two-spar roll-attenuation pitch-attenuation suspension system, generally referenced by numeral  650 , mounted to a deck  204 . In  FIGS. 54 through 56 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 57 and 58 , the embodiment is shown with the marine platform  200  in a compressed position. In  FIGS. 59 and 60 , the embodiment is shown with the marine platform  200  rolled to port and with forward-end-down pitch, both relative to the deck  204 . 
     In the embodiment shown in  FIGS. 54 through 60 , the single one-spar-two-spar roll-attenuation pitch-attenuation suspension system  650 , includes four struts  206 , a roll-attenuation assembly  220 , a pitch-attenuation assembly  230 , and three spars  270 . The three spars  270  are arranged in the shape of a V, with two of the spars  270  adjacent and parallel to each other, and defining one side of the V, and the third spar  270  defining the other side of the V; and with the base of the V attached to the marine platform  200  and the top of the V attached to the deck  204 . 
     Referring to  FIGS. 61 through 67 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated single two-spar-two-spar roll-attenuation pitch-attenuation suspension system, generally referenced by numeral  700 , mounted to a deck  204 . In  FIGS. 61 through 63 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 64 and 65 , the embodiment is shown with the marine platform  200  in a compressed position. In  FIGS. 66 and 67 , the embodiment is shown with the marine platform  200  rolled to port relative to the deck  204 . 
     In the embodiment shown in  FIGS. 61 through 67 , the single two-spar-two-spar roll-attenuation pitch-attenuation suspension system  700 , includes four struts  206 , a roll-attenuation assembly  220 , a pitch-attenuation assembly  230 , and four spars  270 . The four spars  270  are arranged in the shape of a V, with two of the spars  270  adjacent and parallel to each other, and defining one side of the V, and the other two of the spars  270  adjacent and parallel to each other, and defining the other side of the V; and with the base of the V attached to the marine platform  200  and the top of the V attached to the deck  204 . 
     Referring to  FIGS. 68 through 74 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated single three-spar-splayed roll-attenuation pitch-attenuation clevis-mount suspension system, generally referenced by numeral  750 , mounted to a deck  204 . In  FIGS. 68 through 70 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 71 and 72 , the embodiment is shown with the marine platform  200  in a compressed position. In  FIGS. 73 and 74 , the embodiment is shown with the marine platform  200  rolled to port relative to the deck  204 . 
     In the embodiment shown in  FIGS. 68 through 74 , the single three-spar-splayed roll-attenuation pitch-attenuation clevis-mount suspension system  750 , includes four struts  206 , a roll-attenuation assembly  220 , a pitch-attenuation assembly  230 , and three spars  270 . The three spars  270  are generally splayed in that the spars  270  diverge in that the ends of the spars  270  mounted to the marine platform are closer one to the other than the ends of the spars  270  mounted to the deck  204 . 
     As indicated most clearly in  FIG. 72 , in the single three-spar-splayed roll-attenuation pitch-attenuation clevis-mount suspension system  750 , the middle spar  270  and starboard-side spar  270  are mounted to the deck  204  with a spar clevis bracket  274 ; and the middle spar  270  and port-side spar  270  are mounted to the marine platform  200  with a spar clevis lateral bracket  276 . 
     Referring to  FIGS. 75 through 81 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated single three-spar-splayed roll-attenuation pitch-attenuation suspension system, generally referenced by numeral  800 , mounted to a deck  204 . In  FIGS. 75 through 77 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 78 and 79 , the embodiment is shown with the marine platform  200  in a compressed position. In  FIGS. 80 and 81 , the embodiment is shown with the marine platform  200  rolled to starboard relative to the deck  204 . 
     In the embodiment shown in  FIGS. 75 through 81 , the single three-spar-splayed roll-attenuation pitch-attenuation suspension system  800 , includes four struts  206 , a roll-attenuation assembly  220 , a pitch-attenuation assembly  230 , and three spars  270 . The three spars  270  are generally splayed in that the spars  270  diverge in that the ends of the spars  270  mounted to the marine platform are closer one to the other than the ends of the spars  270  mounted to the deck  204 . 
     Referring to  FIGS. 82 through 88 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated single three-spar Z-style roll-attenuation pitch-attenuation suspension system, generally referenced by numeral  850 , mounted to a deck  204 . In  FIGS. 82 through 84 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 85 and 86 , the embodiment is shown with the marine platform  200  in a compressed position. In  FIGS. 87 and 88 , the embodiment is shown with the marine platform  200  rolled to starboard relative to the deck  204 . 
     In the embodiment shown in  FIGS. 82 through 88 , the single three-spar Z-style roll-attenuation pitch-attenuation suspension system  850 , includes four struts  206 , a roll-attenuation assembly  220 , a pitch-attenuation assembly  230 , and three spars  270 . The three spars  270  are generally arranged in the form of a Z, in that the two outer spars  270  (i.e., the spar  270  that is furthest starboard and the spar  270  that is furthest port) are essentially parallel one to the other, and the middle spar  270  extends essentially diagonally between them, extending from the vicinity of the end of the starboard-side spar  270  mounted to the deck  204  to the vicinity of the end of the port-side spar  270  mounted to the marine platform  200 . 
     Referring to  FIGS. 89 through 95 , there is illustrated an embodiment of the present invention comprising a marine platform  200  and an associated single three-spar Z-style roll-attenuation pitch-attenuation clevis-mount suspension system, generally referenced by numeral  900 , mounted to a deck  204 . In  FIGS. 89 through 91 , the embodiment is shown with the marine platform  200  in a no-load at-rest position. In  FIGS. 92 and 93 , the embodiment is shown with the marine platform  200  in a compressed position. In  FIGS. 94 and 95 , the embodiment is shown with the marine platform  200  rolled to starboard relative to the deck  204 . 
     In the embodiment shown in  FIGS. 89 through 95 , the single three-spar Z-style roll-attenuation pitch-attenuation clevis-mount suspension system  900 , includes four struts  206 , a roll-attenuation assembly  220 , a pitch-attenuation assembly  230 , and three spars  270 . The three spars  270  are generally arranged in the form of a Z, in that the two outer spars  270  (i.e., the spar  270  that is furthest starboard and the spar  270  that is furthest port) are essentially parallel one to the other, and the middle spar  270  extends essentially diagonally between them, extending from the vicinity of the end of the starboard-side spar  270  mounted to the deck  204  to the vicinity of the end of the port-side spar  270  mounted to the marine platform  200 . 
     As indicated most clearly in  FIG. 93 , in the single three-spar Z-style roll-attenuation pitch-attenuation clevis-mount suspension system  900 , the middle spar  270  and starboard-side spar  270  are mounted to the deck  204  with a spar clevis bracket  274 ; and the middle spar  270  and port-side spar  270  are mounted to the marine platform  200  with a spar clevis lateral bracket  276 . 
     Referring to  FIGS. 99 to 110  there are shown movement-accommodating spar brackets which permit relative fore and aft movement as between the spars  270  (or forward wishbone  302  or aft wishbone  304 ) and marine platform  200 , or the deck  204 , that the movement-accommodating spar bracket is interconnecting. The movement-accommodating spar bracket embodiments illustrated in the drawings are a sliding spar bracket  930  and pivoting spar bracket  950 , which are configured for interconnecting two spars  270  to a marine platform  200 . 
     As indicated in  FIGS. 99-102 , the sliding spar bracket  930  comprises a track assembly  922  and a slide assembly  924 . 
     The track assembly  922  comprises two spaced-apart parallel tracks  926  having a general “T” configuration. The track assembly  922  may also include a track mount  928 , being, in the embodiments shown in the drawings, a plate suitable for maintaining the relative orientation of the tracks  926  during use and for affixing to the marine platform  200 . Alternatively, the tracks  926  may be affixed directly to the marine platform  200 . 
     The slide assembly  924  comprises a slide assembly body  930 , two spar connectors  932  on the lower side of the slide assembly body  930  and two spaced apart aligned car assemblies  934  on the upper side of the slide assembly body  930 . 
     Each spar connector  932  comprises two parallel projecting tangs  936  configured (including each having a hole therethrough) for receiving the heir joint  314  of a respective spar  270  and securing same with a heim joint fastener  938 . The spar connectors  932  are angled relative to each other so as to be aligned with a pair of spars  270  oriented in the shape of a V, with the base of the V attached to the spar connectors  932  and the top of the V attached to the deck  204 . 
     Each car assembly  934  comprises one or more aligned cars  940  configured for slidable engagement with a respective track  926 . As will be apparent from the drawings, when engaged one with the other, the slide assembly  924  and track assembly  922  are constrained to undergoing relative reciprocating linear movement. 
     To obtain the desired alignment (and thus low friction), as the slide assembly body  930  is preferably metal (preferably stainless steel plate) and the tangs  936  are preferably welded to the slide assembly body  930 , the face of the slide assembly body  930  to which the tracks  926  are affixed, is preferably machined after the tangs  936  are attached to remove any distortion caused by the welding. 
     Given the marine environment to which they are exposed in use, the tracks  926  and cars  940  are preferably corrosion resistant and low friction without lubrication. The tracks  926  are preferably anodized aluminum T-rail. The cars  940  preferably comprise anodized aluminum bodies with low-friction plastic sliding elements. 
     It has been found that products provided by IGUS GmbH and IGUS Inc. are suitable for use as cars  940  and tracks  926 , namely DryLin@ T—profile rail series, specifically car part no. TW-01-25 and rail part no. TS-01-25 (the car is 6063-T6 Aluminum and clear anodized, and the rail is 6063-T6 Aluminum and hard anodized). The IGUS GmbH and IGUS Inc. cars in include a sliding element made from iglide@ J material and the sliding elements are adjustable with stainless steel screws. 
     As indicated in  FIGS. 103 and 104 , the pivoting spar bracket  950  comprises a pivot block  952 , a pivot cavity  954  and pivot pin assembly  956 . 
     The pivot block  952  includes two spar connectors  932  oriented in the same manner as the spar connectors  932  of the sliding spar bracket  920 . The pivot block  952  includes a pivot block bore  958 . 
     The pivot cavity  954  includes a recess for receiving the pivot block  952  and two pivot cavity holes  960 . The pivot cavity  954  may be a separate component affixed to the marine platform  200  or may be integral to the marine platform  200 . 
     The pivot pin assembly  956  includes a pivot bolt  962 , pivot nut  964 , pivot washer  966 , two pivot sleeves  968  and a pivot bushing  970 . 
     The pivoting spar bracket  950  is assembled by: inserting a pivot sleeve  968  into each end of the pivot block bore  958 ; inserting the pivot bushing  970  into the pivot sleeves  968 ; positioning the pivot block  952  within the pivot cavity  954  so as to bring the pivot block bore  958  into alignment with the pivot cavity holes  960 ; inserting the pivot bolt  962  therethrough; and securing the pivot bolt  962  with the pivot nut  964  and pivot washer  966 . 
     It has been found that the Iglide® J material provided by IGUS GmbH and IGUS Inc. is suitable for use as pivot bushing  970 , for example bushing part no: JFI-2428-24. 
     Double two-spar roll-attenuation embodiments of the present invention with movement-accommodating spar brackets are shown in the drawings. 
       FIGS. 105 and 106  show a double two-spar roll-attenuation embodiment of the present invention with movement-accommodating spar brackets wherein the forward spars  270  are interconnected to the marine platform  200  via a sliding spar bracket  920  and the torsion spring  242  is attached to the marine platform  200  roughly in the middle of the fore and aft extent of the marine platform and with the adjustable torsion arms  246  extending aft from the torsion spring  242 . 
       FIGS. 107 and 108  show a double two-spar roll-attenuation embodiment of the present invention with movement-accommodating spar brackets wherein the aft spars  270  are interconnected to the marine platform  200  via a sliding spar bracket  920  and the torsion spring  242  is attached to the marine platform  200  toward the forward end of the marine platform and with the adjustable torsion arms  246  extending forward from the torsion spring  242 . 
       FIGS. 109 and 110  show a double two-spar roll-attenuation embodiment of the present invention with movement-accommodating spar brackets wherein the aft spars  270  are interconnected to the marine platform  200  via a pivoting spar bracket  950  and the torsion spring  242  is attached to the marine platform  200  toward the forward end of the marine platform and with the adjustable torsion arms  246  extending forward from the torsion spring  242 . 
     It will be apparent that the movement-accommodating spar brackets permit relative differential vertical movement as between the forward and aft portions of the marine platform  200 , which improves suspension performance in terms of response to pitch. 
     The sliding spar bracket  920  and pivoting spar bracket  950  are preferably configured to accommodate the maximum permitted differential movement as between the forward and aft portions of the marine platform  200 , in terms of the simultaneous maximum compression of the forward struts  206  and maximum extension of the aft struts  206 , or the simultaneous maximum extension of the forward struts  206  and maximum compression of the aft struts  206 . 
     Similar permitted relative differential vertical movement as between the forward and aft portions of the marine platform  200  could be provided by interconnecting the two spars  270  to the deck  204  with a movement accommodating mounting (not shown), although it is understood that it is simpler and thus preferably to have a single movement accommodating component there the spars  270  converge (i.e., as described above).