we use the Solvit ramp. Found out some things the hard way:
1. Drill a hole, attach a line that hooks to the cleat on the swim platform, always! You are so right..it floats but briefly.
2. NEVER leave the ramp deployed. Always take it off, leave it ready to deploy..

And other hard lessons, if we are underway or moving on and off boat, Tugboat (95 pound American bulldog mix) will always have his life jacket on – it has a handle, you know. Not fun trying to fish a very large dog out of the water with only a collar on. He has tried to follow us on to the dock by walking the very narrow ledge (too narrow for him) from the pilot house door left open on the water side. We securely closed the door on the dock side -he will leap that 4 ft jump every time.

Sadly, these lessons were learned after we lost our previous dog to drowning when our ramp came away from the dock as he was coming out to us sitting on the dock. He lasted a few days, but succumbed to pneumonia after 5 days in the hospital.