I had the same problem with my Nomad and based on internet research also got the Seals Pro Rand 1.4. It solved my problem but the skirt is easy to get on and definitely not tight - actually to the point that I was a little worried it might not be tight enough, but I've plugged some waterfalls at this point and am convinced it's bomber.
So my only 2 cents is it has a really beefy rand (more so by far than I've seen) and therefore doesn't need a tight fit to seal the cockpit. In fact, I think it's a bad idea to have a skirt on a creekboat that is hard to get on because often you need to jump in your boat fast and/or do it from a precarious launch spot. I remember doing a 20 feet seal launch teetering on a rather sketchy perch on a creek in WA - you really want to be cranking on your skirt trying to get it on then?
You might also try putting a strip of weather sealing around (under really) your cockpit rim. I think it helps - at least a little bit.