A watercraft transport lock includes a walled structure that can be filled
and emptied of water received from two separate bodies of water for the
purpose of transporting a boat or other watercraft between the two bodies
of water. The system prevents the water of one body from mixing with the
water of the other body. This is accomplished by removing the water of
the first body of water from within the structure prior to filling the
structure with the water from the other body. A boat support may be used
to support the boat during the emptying and filling processes.