Last year I did some searching and testing for replacement knee pucks / knee sliders. The results of that time left me with one answer/product: Klucky Pucks.

The Klucky pucks have a high quality Velcro back that in my 3 sets so far has yet to fail me in any way. The slider material is a hard semi-greasy almost consistency that provides solid feedback/drag from the track yet slides well, doesn't get caught up, and more importantly doesn't seem to over heat and melt like many others.

If my review or preference for them isn't enough, apparently RoadRacing World rates them #1 in their tests as well. Unfortunately I've only seen references to this test and not the actual article...

While so far I have been using the same sliders for wet and dry events; I would most likely recommend a softer puck for water on the track conditions. These might not give you enough feed back or drag in rainy / wet environments.