The SCI-Nurses are advanced practice nurses specializing in SCI/D care. They are available to answer questions, provide education, and make suggestions which you should always discuss with your physician/primary health care provider before implementing. Medical diagnosis is not provided, nor do the SCI-Nurses provide nursing or medical care through their responses on the CareCure forums.
Instead of a diving board how about a slide and sling powered by the hoist?
My brother built one, similar to the lift for my van, using the hoist from Harbor Freight. The arm rotated on a steel column and I used a sling, it was super trick. Do worry about the electric, just make sure it's a GFCI protected dedicated circuit. You could have a welder put it together for not too much $$$$ I used it quite a bit about 20 years ago...never failed. I'm not here often, text if you want more info.