Thinking of making pretty much the same trip, myself, as I am close to the Hudson, just a little further up stream, but not planning to all the way to Vermont. Have freinds North of Albany to boat with.
Just a thought, I believe removing the valve handle / locking handle is OK, legally. Disable the pump by pulling the fuse or disconnecting the wiring harness to it. Just check for yourself, as I am no legal expert, but I am pretty sure that is what is suggested on vessels used in various bodies of water. I believe the purpose is so it can't be "accidently" changed without use of tools / keys. Any wronful discharge would be the result of intentionally and/or manually changing lineup, hence allowing it to happen, making you liable, if caught.