A kickboard for a swimmer which has a rigid, smoothly contoured, buoyant body symmetrical about a longitudinally extending notional plane perpendicular to its top surface and passing through a center thereof. When referenced to the kickboard being supported by a flat horizontal support surface, the top surface is inclined rearwardly, along the intersection with the notional plane, from a front peripheral edge and upwardly from the support surface reaching a maximum and then curving downwardly toward the sides and in a rearwardly direction. A central curvilinear opening extends from proximal the maximum with opening peripheral side edges extending rearwardly, spaced away from respective outer peripheral side edges of the body so as to provide contoured elongated arm receptacles. A bottom surface of the body follows a similar profile as the overlying top surface.

FIELD 
The present invention relates to a kickboard for a swimmer which can be 
used for either strengthening the legs by holding the kickboard with the 
arms or by engaging the kickboard with the legs and exercising the arms 
and upper body. 
BACKGROUND 
The most popular conventional kickboard consists of a buoyant rectangular 
shaped flat body having a slightly rounded front periphery. The latter 
kickboard offers little streamlining and provides a significant resistance 
to forward propulsion by the swimmer. Consequently, a beginning swimmer is 
not generally able to propel this board with significant speed and an 
intermediate or advanced swimmer cannot propel the board with a speed that 
is similar to that which he or she can achieve by normal swimming. 
U.S. Pat. No. 4,362,518 issued to Boissiere discloses a foam kickboard with 
rounded edges having a pair of flat, elongated thickened flanks joined by 
a thinner central, flat web with hand-hold recesses on the sides. 
Boissiere discloses no streamlining of the bottom or top surfaces. 
U.S. Pat. No. 4,886,476 issued to Winters, Jr. discloses a kickboard having 
a forward planar portion inclined upwardly from a flat, rear portion. The 
buoyancy of the flat rear portion may be varied by filling it with a 
selected amount of liquid. No streamlining of the top and bottom surfaces 
is evident in this patent. 
Another problem with the conventional kickboard that is shared by those of 
the above-mentioned references is that they support the swimmer in a 
position that does not correspond to the posture assumed while swimming. 
Consequently, prolonged use often causes soreness of the back. 
Accordingly, it is an object of the present invention to provide an 
improved kickboard for a swimmer. It is a further object of the invention 
to provide a kickboard whose top and bottom surfaces are contoured to 
achieve improved streamlining. It is yet a further object of the invention 
to provide a kickboard which holds the swimmer at a level in the water 
which corresponds substantially with that assumed during normal swimming. 
SUMMARY OF THE INVENTION 
According to the invention there is provided a kickboard for a swimmer 
having a rigid, smoothly contoured, buoyant body symmetrical about a 
longitudinally extending notional plane perpendicular to its top surface 
and passing through a center thereof. When referenced to the kickboard 
being supported by a flat horizontal support surface, the top surface is 
inclined rearwardly, along the intersection with the notional plane, from 
a front peripheral edge and upwardly from the support surface, reaching a 
maximum and then curving downwardly toward the sides and in a rearwardly 
direction. A central curvilinear opening extends rearwardly from proximal 
the maximum and has opening peripheral side edges extending rearwardly, 
spaced away from respective outer peripheral side edges of the body so as 
to provide contoured elongated arm receptacles whose upper surfaces are 
concave upwardly. A bottom surface of the body follows a similar profile 
as the overlying top surface. 
Preferably, a bottom surface of the kickboard in the forward region from a 
front periphery toward the opening defines an inverted gradually narrowing 
trough so that, when in operation, it directs water flow through the 
opening with little or no turbulence. The sides of the kickboard may 
diverge slightly from front to back. 
Advantageously, the opening is curvilinear and of increasing width from 
front to approximately one-half its length toward the back. For 
approximately three-quarters the length of the body, the top surface of 
the kickboard along the arm receptacles may be lower than the center along 
a longitudinal axis thereof. The top surface of the body may also 
substantially conform in shape to the bottom surface thereof. The opening 
may extend to the rear periphery thereof or, alternatively, may extend 
only to a region spaced toward the front from the rear periphery. 
The arm receptacles which, when viewed from the side in elevation, are 
S-shaped allow the user to hold the front portion substantially parallel 
to the surface of the water with the rear portion inclined slightly 
downwardly and rearwardly, so that the shoulders and front torso may be 
positioned lower in the water. Such positioning helps alleviate excess 
strain on the lower back.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS 
Referring to FIGS. 1, 3 and 4, the kickboard 10 has generally curvilinear 
periphery 11 with a rounded front 12, slightly diverging sides 16 and a 
generally transverse rear periphery 14. An opening 18 in the central 
region of the kickboard 10 is rounded at a forward end 20 and diverges 
towards a back end 22 spaced away from the rear periphery 14. With the 
kickboard 10 resting upon a flat, horizontal surface, a top surface 26 
along bisecting line 24 near the front 12 is inclined linearly upwardly 
towards a maximum 28 at which region the top surface 25 is rounded and 
then progresses slightly downwardly before terminating at the forward end 
20 of opening 18. The sides 29 on each side of opening 18 define a pair of 
arm receptacles which accommodate the arms of a user whose hands grip the 
front 12. 
Referring to FIG. 2, the bottom surface 32 of kickboard 10 generally 
conforms in shape to the top surface 26 except that the kickboard 10 is 
slightly thicker near the center than at the edges in the forward region. 
Region 30 with the kickboard 10 upside down on a flat horizontal surface 
defines a funnel-shaped channel with the rounded bottom becoming narrower 
and the sides steeper as one progresses towards forward end 20 of opening 
18 from the front 12. Referring to FIGS. 5, 6 and 7 it is seen that the 
bottom surface 32 progresses from having only slightly inclined sides as 
shown in FIG. 5 to slightly more inclined sides in FIG. 6 to more steeply 
inclined sides and a distinctly rounded bottom as shown in FIG. 7. 
Referring to FIG. 8 it is seen that a swimmer grasps the front of the 
kickboard 10 with his hands and with his arms extending along the arm 
receptacles 29. In this position the top surface 26 near the front 12 is 
nearly flat while the arm receptacles 29 are generally inclined downwardly 
into the water. As the user kicks his legs to propel himself and the 
kickboard 10 forward through the water, water is funneled into opening 18 
so that a smooth flow is established along the bottom region 30. The 
smooth contoured surface along the underside of the arm receptacles also 
promotes smooth non-turbulent flow of the water. With the arm receptacles 
29 lower in elevation than the top surface along the centre axis, a 
swimmer may be positioned so that his shoulders and torso are lower in the 
water. This positioning reduces the strain on a swimmer's lower back. 
Referring to FIGS. 9, 10 and 11, a variant of the kickboard 40 is identical 
to kickboard 10 except that opening 48 opens to the rear periphery 14. The 
thickness of the kickboard 40 can be increased gradually toward the rear 
periphery 14 depending upon the angle or tilt of the kickboard 40 required 
when in use, the object being to have the top surface 26 near the front 
substantially horizontal. 
Accordingly, while this invention has been described with reference to 
illustrative embodiments, this description is not intended to be construed 
in a limiting sense. Various modifications of the illustrative 
embodiments, as well as other embodiments of the invention, will be 
apparent to persons skilled in the art upon reference to this description. 
It is therefore contemplated that the appended claims will cover any such 
modifications or embodiments as fall within the true scope of the 
invention.