Hey Ock,
have noticed your absence at Deadman's since the weather turned.
I paddled Sat am [ 7 degrees] and this morning [ 4 degrees] and think I layered up fairly accurately.
I assuming you're not planning on taking a spill, so I'd be recommending the following.
- bottoms / Skins or any decent compression brand. I use the following
http://www.zootsports.com/spring2010/product/m-compressrx-active-tight?category=mens%2Fcompression- top. I've just been wearing the long sleeve thermals I usually wear when I cycle and layer up with either a cycling vest which has a full front zip and a mesh back [kinky, eh?] for venting. It's light, compact and windproof and can easily be stashed when you start to over-heat. This morning being colder I went for a stretch fleece rather than a vest and added a beanie. I'd say for you that any neoprene based garment may get a bit too warm given they don't breathe.
-Feet. I will eventually start using my reef boots when the water drops to below 14 degrees.
If you have a peek in at Le Knicks at the clocktower, he's got loads of sale cycling vests, etc out front.