All good considerations, generally speaking. However, the ferry I had planned to jump off is crossing depths greater than 600', and it's very cold water, so the chances are excellent that any decomposition would be at a very, very slow pace. It's quite likely my body would be eaten before anything identifiable made it to shore. So long as I choose my clothes with care --leather shoes, natural fiber fabrics; nothing synthetic that will add buoyancy-- I'm confident I at least have a very good chance of indiscoverably resting in genuine peace.
At Lake Tahoe, another very deep, very cold body of water, it is well known that drowning victims typically never reemerge from the depths: the water is too cold to allow bloating. The bodies become fish food before they can float up and be found, and finding bones at that depth is highly unlikely.
