I wanna build a boat.

Subject matter changed, we were discussing general boat plans, the other thread now is about a specific thread

 

Don't use a tin shed, they get a lot of condensation inside. And are noisy when it rains..

 

Unless you are planning to portage the boat around the locks, the plan won't work. You need to enter and exit under power. Also, they won't allow into the locks if your boat does not appear to be safe. The locks are shared with commercial traffic. The current and turbulence is very high.