It is the same ramp. What changes is everything around it — how it is anchored, how steep it sits, and what the water does to it.
Anchoring
At a pool you usually have a rail, a ladder or a solid edge, and the ramp stays where you put it. On a boat the whole platform is moving. Use all four D-rings and both 8 ft ropes, tie to cleats rather than rails where you can, and check the tension after the first swim — rope stretches and knots settle.
Freeboard changes the angle
A pool coping sits a few inches above the water. A pontoon deck can sit two feet or more. The higher the deck, the steeper the ramp, and steep is the single biggest reason a dog refuses. If your freeboard is high, run the ramp out at a shallower angle even if it means it reaches further from the hull.
Salt water is the difference that matters long term
The pad material is salt and UV resistant, but resistant is not the same as unaffected. Rinse with fresh water after every saltwater trip. Salt left to dry works into seams and fittings, and the D-rings and valve are where you will notice it first.
Protecting the hull
This is often the actual reason people buy a ramp. A big dog trying to get back aboard over the gunwale will scratch gelcoat, and a claw across a swim platform is a repair. An inflatable ramp puts a soft, claw-resistant surface between the dog and your boat.
Storage
On a boat, storage volume is currency. Deflated and rolled, the ramp fits in the supplied bag and goes under a bench seat. Make sure it is dry before it goes in — a damp bag in a hot locker is how mildew starts.
Docks are the easy case
A fixed dock gives you solid anchor points and a consistent height, which makes it the best place to introduce the ramp to a nervous dog. If you have access to one, start there before you try it off the back of a moving boat.
