The boat launch normally drops off at the Marketplace (near the Rainforest Cafe), but I believe if you specifically request it to the driver, they will drop you off on the West Side---near the House of Blues maybe ? Not sure if they come back there for the return trip to OKW though ? Maybe someone else will have the answer for that.
It's about a 15+ min boat ride. I've never walked there, so I can't comment on how long that would take.