As Ann noted, this has been discussed at some length on this forum with very few "dog negative" comments. We're sailors - give us a problem and we'll make it work
, not tell you to leave your problem at home. As everyone notes, the issue with dog ramps is that when you're using them you want them large and robust, and when you're storing them you want them light and folded. You want all that convenience for almost no cash. Same problem with boat
poles, fenders, etc. so it's going to be a compromise.
Personally, I modified a purchased dog loading ramp for cars that I bought in a pet store for $100, which folds in half to about 1 meter long. I drilled some holes in the polyethylene plastic and zip-tied some cut-up pool noodles underneath for one end, and strapped the other end to my swim ladder with a 1" web belt that I bought for $3. The critical part of the ramp is that when the dog steps on the outboard
end it should drop underwater to provide a ramp for the hind legs, so balancing flotation is critical and the pool noodles allow for adjustment. You may have to mount some attachment points to your steps. While you're at it, put on another couple of small cleats
back there to tie up your dingy - thus saving yourself a swim when you pull up to unload!