A Proliferation of Noses

[Ichabod Spoonbill]

I was wondering if the forum could clear this up for me. There seem to be two types of noses for flatwater boards. There's a vertical, ship or canoe-like nose, then there's the kayak-style, pointy nose.

I'm guessing the ship-style nose is better for flatwater and the kayak nose is better for choppier water, but I'm sure it's not as simple as that. What are the advantages of each?