I'm using Sitka Spruce in my current boat. I had to pick up a little more Saturday... Sitka Spruce is often used for wooden (sailing) spars and is expensive. I grows only in the coastal Northwest. In Seattle it is over $7 per board foot. It's pretty hard to find Sitka Spruce - even in its native region. I know of only one local yard that stocks it - the boards are rough sawn to various lengths of 1x and 2x.

I assume the generic Spruce at my neighborhood lumber yard is White Spruce. It shares some of the characteristics of Sitka Spruce (relatively straight grain, strong for its weight) but it is a lighter color. White Spruce also grows across much of North America so it's cheaper. Crooks cut from the roots of White Spruce (Adirondack Spruce) were classically used in the construction of Adirondack Guide Boats. I don't recall off the top of my head if Spruce was used on other parts of the boat.

Both varieties seem very stiff compared to say Western Red Cedar - the White Spruce feels very hard. I love reading about the different characteristics of wood but there is no substitute for testing things out yourself.