Ted Edwards wrote:
Gary Coffman wrote:

Actually, in the boat it displaces its *weight*, not mass, but otherwise
correct.

Unless the boat and block are in different gravitational fields, the
result is the same. W=mg.

The boat and the block are in different gravitational fields.
Say the block is moved down 2m from its position in the boat.

Now, fun question.
Is it now slightly heavier, slightly lighter, or the same weight.