Bottom for planing boats

This invention relates to a step construction for a bottom of planing boats in which the step angle is adjusted to the flow direction of the water under each part of the boat bottom. Each step is so designed that the flow direction of the water when the boat is driven at planing speeds is essentially perpendicular thereto under as great a part of the step as possible.

I claim:

1. A bottom for planing boats comprising a plurality of steps located on said bottom, at least said steps on the rearward portion of said bottom being located substantially at the chine line of the bottom, said steps located on the forward portion of said bottom being spaced from the chine, the rearward portion of said steps being curved and the outward and forward portion thereof being substantially parallel to the keel of said bottom and the rearward and inward portion being spaced from said keel and being substantially perpendicular thereto, said curve of said step being a substantially smooth curve, and the maximum deflection of said curve being greater substantially at the middle portion of said steps, whereby the curve is substantially perpendicular at every point thereon to the direction of flow of water when the boat is planing.

2. A bottom for planing boats according to claim 1, wherein the height of said steps at the forward portion thereof is minor and increases evenly in the rearwardly direction to a maximum at the middle portion of the steps.

3. A bottom for planing boats according to claim 2, wherein a portion of the surface of at least one step located essentially at the forward portion extending to and including the portion of the maximum deflection of the curve is of a lesser slope in relation to the horizontal plane than the neighboring portions of said steps to form a plane, said plane extending essentially in the longitudinal direction with respect to the bottom.

4. A bottom for planing boats according to claim 1, wherein said height of said steps inwardly of said middle portion evenly decreases to zero as the distance from said chine increases.

5. A bottom for planing boats according to claim 1, wherein the outward and forward portion of said steps forms an angle of from 0.degree. to 10.degree. with the chine.

6. A bottom for planing boats according to claim 1, wherein the distance from the front to the back of said steps is in the range of from 20 to 120 cms.

7. A bottom for planing boats according to claim 6, wherein the maximum height of said steps is in the range of from 10 to 120 mms.

8. A bottom for planing boats according to claim 1, wherein the steps that are spaced from said chine are in the forward quarter of said bottom, said distance between said step and said chine decreasing with each rearwardly located step.

9. A bottom for planing boats comprising a plurality of steps located on said bottom, at least said steps on the rearward portion of said bottom being located substantially at the chine line of the bottom, said steps located on the forward portion of said bottom being spaced from the chine, the rearward portion of said steps being curved and the outward and forward portion thereof being substantially parallel to the keel of said bottom and the rearward and inward portion being spaced from said keel and being substantially perpendicular thereto, said curve of said step being a substantially smooth curve, and the maximum deflection of said curve being greater substantially at the middle portion of said steps, the height of said steps at the forward portion thereof is minor and increases evenly in the rearwardly direction to a maximum at the middle portion of the steps, the height of said steps located inwardly of said middle portion being substantially the same as the height of said middle portion, and at least one triangular surface located at the rearward and inward portion of at least one of said steps being of substantially triangular configuration and defining a substantially vertical surface located on said bottom, said triangular surface extending substantially parallel with the keel.

10. A bottom for planing boats according to claim 9, further comprising a plurality of longitudinal strips, at least one of said strips being located on each side of the keel of said bottom, said strips being in juxtaposition with at least one of said triangular surfaces and having a substantially vertical outwardly facing surface.

11. A bottom for planing boats according to claim 9, wherein the sides of the steps are concaved.

12. A bottom for planing boats comprising a plurality of steps located on said bottom, at least said steps on the rearward portion of said bottom being located substantially at the chine line of the bottom, said steps located on the forward portion of said bottom being spaced from the chine, the rearward portion of said steps being curved and the outward and forward portion thereof being substantially parallel to the keel of said bottom and the rearward and inward portion being spaced from said keel and being substantially perpendicular thereto, said curve of said step being a substantially smooth curve, and the maximum deflection of said curve being greater substantially at the middle portion of said steps, the height of said steps at the forward portion thereof is minor and increases evenly in the rearwardly direction between maximum at the middle portion of the steps, the height of said steps located inwardly of said middle portion being substantially the same as the height of said middle portion, and at least one triangular surface located at the rearward and inward portion of at least one of said steps being of substantially triangular configuration, and defining a substantially vertical surface located on said bottom, said triangular surface extending substantially parallel with the keel, and a plurality of longitudinal channels being located in said bottom, said channels being substantially parallel with the keel and located inwardly of said steps on either side of the keel.

13. A bottom for planing boats comprising a plurality of steps located on said bottom, at least said steps on the rearward portion of said bottom being located substantially at the chine line of the bottom, said steps located on the forward portion of said bottom being spaced from the chine, the rearward portion of said steps being curved and the outward and forward portion thereof being substantially parallel to the keel of said bottom and the rearward and inward portion being spaced from said keel and being substantially perpendicular thereto, said curve of said step being a substantially smooth curve, and the maximum deflection of said curve being greater substantially at the middle portion of said steps, the height of said steps at the forward portion thereof is minor and increases evenly in the rearwardly direction between maximum at the middle portion of the steps, the height of said located inwardly of said middle portion being substantially the same as the height of said middle portion, and at least on triangular surface located at the rearward and inward portion of at least one of said steps being of substantially triangular configuration, and defining a substantially vertical surface located on said bottom, said triangular surface extending substantially parallel with the keel, and a plurality of longitudinal channels being located in said bottom, said channels being substantially parallel with the keel and located inwardly of said steps on either side of the keel, and a plurality of longitudinal strips located on either side of said keel, said strips being in juxtaposition with said triangular surfaces and having a substantially vertical surface facing outwardly, said longitudinal strips and said channels being disposed parallel to each other, said channels being located outwardly of said strips.