Steerable towcraft having a buoyant body upon which a person can ride, a towline attached to body and adapted for connection to the pulling vessel, a fin on the under side of the body for guiding the body through water, and a steering line connected to the towline at a point spaced from the body. By pulling on the steering line, a person riding on the body can change the angle of the fin relative to the towline, and thereby control the direction in which the towcraft is moving.

BACKGROUND OF THE INVENTION 
This invention pertains generally to water sports and, more particularly, 
to watercraft of the type towed behind a boat or other vessel. 
Children and others enjoy being towed behind boats on a variety of buoyant 
devices such as inner tubes and the like. Such devices are generally 
attached to the towing vessels by towlines, and there is no way to steer 
them. They simply go where the boat takes them, and that can become 
relatively unchallenging and/or uninteresting when the boat is going 
slowly and in a straight line. 
At higher speeds, when the boat makes a turn, centrifugal force can cause 
the device to swing outside the wake of the boat and to travel 
substantially farther and faster than the boat itself is travelling. The 
rider has no control over where or how fast he is going, and in the event 
of debris or other obstacles in the water, about all the rider can do to 
protect himself is let go of the line or fall off the device. With a boat 
travelling at a speed of 25 mph, the tube can travel at speeds as high as 
40 to 50 mph, or more, and jumping or falling into the water at those 
speeds is not something that most people would want to do. 
OBJECT AND SUMMARY OF THE INVENTION 
It is in general an object of the invention to provide a new and improved 
towcraft for riding behind boats and other pulling vessels. 
Another object of the invention is to provide a towcraft of the above 
character which overcomes the limitations and disadvantages of the prior 
art. 
Another object of the invention is to provide a towcraft of the above 
character which can be steered by a person riding thereon. 
These and other objects are achieved in accordance with the invention by 
providing a steerable towcraft which has a buoyant body upon which a 
person can ride, a towline attached to body and adapted for connection to 
the pulling vessel, a fin on the under side of the body for guiding the 
body through water, and a steering line connected to the towline at a 
point spaced from the body. By pulling on the steering line, a person 
riding on the body can change the angle of the fin relative to the 
towline, and thereby control the direction in which the towcraft is moving 
.

DETAILED DESCRIPTION 
As illustrated in FIGS. 1-3, the towcraft comprises a buoyant body 11 
which, in this particular embodiment, consists of a pneumatically inflated 
tube 12 and a cover or skin 13 which envelopes the tube from below. The 
tube is fabricated of a material such as vinyl. In plan view, the tube has 
a generally triangular configuration with rounded corners and a central 
opening 14. The cover is fabricated of a material such as nylon. It has a 
bottom wall 16 which extends beneath the tube and a side wall 17 which 
wraps around the sides and over the top of the tube. The cover is open at 
the top, and a person riding on the craft sits or kneels in the cavity 19 
formed by the opening in the tube and the bottom wall of the cover. The 
body is assembled by placing the uninflated tube in the cover and 
inflating it in position. 
Fins 21 are provided on the under side of the body for guiding the craft 
through the water. The number of fins is not critical as long as the fins 
have sufficient overall area to control the direction of the craft. In the 
embodiment illustrated, six fins of generally triangular shape are 
provided. With the tube having an inflated diameter on the order of 12 
inches and the body having a length and a width on the order of 4 feet, 
each of the fins can, for example, have a height on the order of 21/2 
inches and a length on the order of 6 inches. 
The fins are molded of a relatively rigid plastic and have base plates 22 
which are affixed to the bottom wall of the cover by suitable means such 
as sewing. The fins are arranged in a symmetrical pattern, with two of 
them lying on the longitudinal centerline toward the front of the body and 
the other four disposed in pairs on opposite sides of the centerline 
toward the rear of the body. 
A towline 24 is attached to the front portion of the body and is adapted 
for connection to a boat or other pulling vessel (not shown). The towline 
consists of a long section 26, a short section 27 and a ring 28 between 
the two sections. The long section is tied or otherwise connected to the 
boat, and the short section is connected to a ring 29 which is attached to 
the nylon cover. 
The longer section can be of any desired length, and the short section 
typically has a length on the order of 2 to 7 feet. 
A steering line 31 is attached to the towline at ring 28. The steering line 
is somewhat longer than the shorter section of the towline, and has a 
handle 32 at its free end which can be grasped by a person riding upon the 
body. With a towline section having a length of 66 inches, for example, 
the steering line can have a length on the order of 80 inches. 
In use, the front section of the towline is tied or otherwise attached to 
the boat, and the towcraft is pulled through the water by that line. The 
person riding on the towcraft holds the handle at the free end of the 
steering line, and pulls on that line when he wants to make a turn. When 
travelling straight ahead inside the boat's wake, the steering line can be 
allowed to slacken since the towline is doing the pulling. 
When the rider wants to make a turn, he leans and pulls on the steering 
line in a direction opposite to the way he wants to go. Thus, to move to 
the right, the rider leans to the left and pulls on the steering line to 
the left of the towline. To move to the left, he leans to the right and 
pulls on the steering line to the right of the towing line. 
Since rings 28, 29 are at relatively fixed points in the towline when that 
line is taut, pulling on the steering line obliquely of the towline causes 
the body to pivot about ring 29. As the body turns, fins 21 also turn, and 
the craft moves in the direction in which the body is headed. 
As illustrated in FIG. 4a, pulling the steering line to the left causes the 
rear of towcraft body to swing to the left, changing the orientation of 
the fins by an angle a and causing the craft to travel to the right. As 
illustrated in FIG. 4b, pulling to the right causes the rear of the craft 
to swing to the right, changing the orientation of the fins by an angle b 
and causing the craft to travel to the left. 
The angle at which the craft turns is dependent upon the angle of the pull 
as well as the distance between the front of the craft and the point at 
which the steering line is connected to the towline, i.e. the distance 
between rings 28 and 29. As noted above, that distance is generally on the 
order of 2 to 10 feet, with about 5 providing particularly good steering 
with a craft of the type and dimensions described above. 
In the embodiment of FIG. 5, a separate steering line 33, 34 is provided 
for each hand. The front portions of these lines are tied or otherwise 
affixed to ring 28, and handles 36, 37 are attached to the free ends of 
the lines. Operation and use of this embodiment is similar to that 
described above, the only difference being that the rider holds one handle 
in each hand and pulls upon the line opposite the direction he wants to 
go. Thus, to travel to the right, he pulls on the line in his left hand, 
and to travel to the left, he pulls on the line in his right hand. 
FIG. 6 illustrates an embodiment similar to that of FIG. 5 except the 
steering line 39 is trained about a pulley 41 attached to ring 28, rather 
than being affixed directly to the ring. Handles 42, 43 are attached to 
the two ends of the steering line, and the direction of travel is 
determined by the net pull exerted on the two ends of the line. Having the 
line trained about the pulley also gives the rider some additional freedom 
of positioning and movement since the relative lengths of line in each 
hand will adjust to accommodate the rider without affecting the steering 
of the craft. 
In the embodiment of FIG. 7, a pair of steering lines 46, 47 with handles 
48, 49 are trained about guides 51 which are affixed to the body on 
opposite sides of the craft. These lines are also trained about a second 
set of guides 52 which are attached to the body in a more central 
position. In the embodiment illustrated, the guides consist of D-rings 
affixed to straps which are sewn to the cover of the body. However, 
pulleys or other suitable types of guides can be employed, if desired. The 
portions of the lines between the guides are covered by patches 56 which 
are sewn to the cover along two opposing edges of the patches to protect 
the rider from contact with the moving lines. 
Operation and use of this embodiment is similar to that of FIG. 5 in that 
the rider simply pulls on the line on the side opposite the direction he 
wants to travel, e.g. pulls left to go right. In this embodiment, however, 
the points at which the pull is applied to the body are fixed by the 
location of guides 51. 
In the embodiment of FIG. 8, a single line 59 is utilized both for towing 
and for steering. The front portion of this line is attached to the boat, 
and the rear portion is split into two sections 61, 62 which are trained 
about guides 63-67. Handles 68, 69 are attached to the free ends of the 
lines. Guides 63, 64 are affixed to the sides of the body toward the front 
of the craft, and guides 66, 67 are located closer to the centerline of 
the craft. The guides are illustrated as being D-rings, but other suitable 
types of guides, including pulleys, can be employed, if desired. 
In operation, the portion of line 59 between the boat and guides 63, 64 
serves as the tow line, with the rider holding onto the two handles rather 
than having the line affixed to the body of the towcraft. To steer, the 
rider pulls harder on one handle than the other. When he does this, the 
body of the craft pivots about the guide 63, 64 on the opposite side of 
the body, and the rear of the craft rotates forward on the side where the 
greater pull is exerted. As in the other embodiments, the rotation of the 
body changes the orientation of the fins and causes the craft to move in a 
direction opposite the side on which the pull is exerted. 
In the embodiment of FIG. 9, the towline includes a pulley 71 which is 
attached to ring 28, and a line bridle 72 which is trained about the 
pulley and attached to rings 73, 74 on opposite sides of the body. 
Steering lines 76, 77 are affixed to ring 28, with handles 78, 79 at the 
ends of the steering lines. 
Operation and use of the embodiment of FIG. 9 is similar to that of FIG. 1. 
However, with line bridle 72 being free to travel about pulley 71, it may 
be possible to turn the craft at greater angles and to travel farther 
outside the wake than in the embodiments where the rear section of the 
towline is affixed to the ring. 
The invention has a number of important features and advantages. It permits 
a person or persons riding on a craft towed by a boat to have complete 
control over where the craft is going. The rider can simply follow the 
boat if he wants, he can cut back and forth either inside or outside the 
wake, and he can steer around debris or other obstacles in the water. 
Also, if the rider wants to rest, he can simply relax the pull on the 
steering line(s) and let the craft follow behind the boat. 
It is apparent from the foregoing that a new and improved steerable 
towcraft has been provided. While only certain presently preferred 
embodiments have been described in detail, as will be apparent to those 
familiar with the art, certain changes and modifications can be made 
without departing from the scope of the invention as defined by the 
following claims.