Hmm that collar was made by someone at a dog show that I picked up, and I'm not sure they had any sort of online presence. I'll check my collection of business cards though and see if I can find anything. 2houndsdesign.com has similar options though if you're looking for something like that.
[Edited to add: That's her "mess collar" now. She broke it a couple of weeks ago]
I've never seen a dane swim, the ones I do see wade in to about their elbows/chest and call it quits there