So what happens if I just pull the nose up and leave it square?

This will sort of ride up over the water if you go fast enough - like waterskiis.

If not, it carries on pushing water along in front of it in a wave like the lego block does. The wave then sort of escapes round the nose on one side or the other sort of at random. This makes the boat change direction - violently.

This is easier to move than a square ended boat/raft, but is still like pushing the boat up hill.

Its also harder to steer than a pointy, but more about that later.

Sorry about the pics quality. They are photos of photos.

Testing the pulled up nose hull in a river.

Two pulled up hulls joined together with a mast and sails.

It was horrible to steer, but it did work.

If you dont mind it wandering off all over the place, this made a boat that would float in 2 inches of water - despite being 7 ft wide and 10 ft long (LWL was nearer 6 1/2ft)