So I wanted to make Knitty's Swell (http://www.knitty.com/issuesummer06/PATTswell.html) for my sea obsessed boyfriend, who has a birthday coming up...

But I can't get the gauge right! I have swatched on every needle size I have (I'm using the yarn the pattern suggests..) from the 3.25mm suggested by the pattern, right up to a 6mm! Even after I've almost doubled my needle size, the minimum number of stitches I can get it down to is 18.

I can't really go up any more, the fabric's looking loose as it is! I really want to make this, but its driving me crazy! Is there something I'm missing? Am I just being genuinely dense? Any suggestions as to what I could do?

I would be eternally greatfull for any help! Thank you!