Help ID alaskan water spider

[buthidae46290]

Hey, Im new to spiders(scorpions are more my thing) I caught a spider at a pond behind my friends house the other day. Its about 1.5-2in. legspan and its mostly black with white markings on the outer edges of its carapace and a white dot in the middle of its abdomen. Hes a pretty fast little guy and Ive been feeding him micro crickets. I'll try to get pics but what do you think it could be?

 

[CedrikG]

does it look like mine I found ? this is an old picture , now she's about 2 inch

 

[buthidae46290]

Very similar to that except mine has another white mark on the center of its abdomen(looks like a bullseye to me) and the dark colored parts are more of a solid black. It could be the same thing though because the patterns are almost identical.
(I caught another yesterday so now I have two males)

 

[buthidae46290]

ive been doin some lookin aound and im 99% sure its a Dolomedes sp...pretty cool little guys.