Collapsible watercraft

1. A collapsible kayak, comprising:

a continuous sheet forming a single-piece hull having a bow portion, a midship portion, and a stern portion, the hull including a plurality of crease lines along which the hull is foldable; and

a floorboard lining the midship portion of the hull between the bow portion and the stern portion, the floorboard including a base and a pair of outboard walls pivotably coupled to the base and permanently fixed at distal ends to port and starboard gunwales of the hull, respectively;

wherein the bow, stern, and midship portions are configured as a tri-fold, such that the bow portion and the stern portion of the kayak are foldable toward each other to overlap the midship portion of the hull when collapsed; and

wherein the floorboard is disposed on a first side of the continuous sheet, and a second side of the continuous sheet opposite the first side faces outward when the kayak is collapsed.

2. The collapsible kayak of claim 1 , further comprising a bulkhead oriented athwartships to close off one end of the hull.

3. The collapsible kayak of claim 2 , wherein the bulkhead is removably held in place by a tether coupled to the hull.

4. The collapsible kayak of claim 2 , wherein the bulkhead includes a pair of pivoting half-walls coupled at outboard ends to the hull, such that the half-walls are configured to meet at inboard ends to form the bulkhead when deployed and to be folded against the hull when collapsed.

5. The collapsible kayak of claim 1 , further comprising a seatback removably coupled to the base of the floorboard.

6. The collapsible kayak of claim 1 , further comprising a removable footrest coupled at opposing outboard ends to the hull.

7. The collapsible kayak of claim 1 , further comprising a closed prow, such that the prow maintains a three-dimensional shape when the kayak is deployed and when the kayak is collapsed.

8. The collapsible kayak of claim 1 , further comprising a closed transom, such that the transom maintains a three-dimensional shape when the kayak is deployed and when the kayak is collapsed.

9. A collapsible watercraft, comprising:

a continuous sheet forming a single-piece hull having a plurality of creases at which the hull is foldable to selectively deploy and collapse the watercraft;

a closed prow at a bow end of the hull and a closed transom at a stern end of the hull; and

an integrated floorboard disposed at a midship section of the hull, at least a portion of the floorboard being permanently fixed to the hull;

wherein the bow end and the stern end are foldable toward the floorboard at respective creases forward and aft of the floorboard to overlap the midship section such that the closed prow and closed transom nest together over the floorboard.

10. The collapsible watercraft of claim 9 , wherein the floorboard comprises a base portion pivotably coupled to a pair of sidewalls, distal ends of the sidewalls being fixed respectively to port and starboard gunwales of the hull.

11. The collapsible watercraft of claim 9 , further comprising a collapsible bulkhead including a pair of partial walls pivotably coupled to the hull, wherein the partial walls are configured to form the bulkhead by pivoting into contact with each other when deployed and to pivot against the hull when collapsed.

12. A method of using a collapsible kayak, the method comprising:

releasing one or more temporary fasteners holding a collapsible kayak in a deployed configuration to cause port and starboard gunwales of the kayak to be moveable in an outboard direction, wherein the kayak has a midship section including an integrated floorboard fixed to an outer hull of the kayak at the port and starboard gunwales, the outer hull formed by a continuous sheet;

folding a first end of the hull of the kayak at a first crease toward a second end of the hull, such that the first end overlaps the integrated floorboard; and

folding the second end of the hull at a second crease to overlap the first end of the hull, such that the first end of the hull nests within the second end of the hull.

13. The method of claim 12 , further comprising:

after folding the first and second ends of the hull at the first and second creases, folding the port and starboard gunwales of the kayak toward each other to form a portable box.

14. The method of claim 12 , wherein a prow at a bow end of the kayak is permanently closed, such that the prow maintains a same three-dimensional shape when the kayak is collapsed and when the kayak is deployed.

15. The method of claim 14 , wherein a transom at a stern end of the kayak is permanently closed, such that the transom maintains a same three-dimensional shape when the kayak is collapsed and when the kayak is deployed.

16. The method of claim 15 , further comprising:

causing the prow and the transom to nest with each other when the first and second ends are folded to overlap the floorboard, such that the three-dimensional shape of the prow and the three-dimensional shape of the transom are each concave with respect to the floorboard.

17. The method of claim 12 , further comprising:

stowing one or more accessories of the kayak between the folded-over first end of the kayak and the floorboard.

18. The method of claim 12 , wherein the floorboard is disposed between the first and second creases.

19. The method of claim 12 , further comprising:

untethering a bulkhead of the kayak from the hull and removing the bulkhead from the kayak.

20. The method of claim 12 , further comprising:

collapsing a bulkhead of the kayak by pivoting wall portions of the bulkhead against the hull.