Waterstrider is a copy of a Watermaster pattern. The WM is built with better material, is built in MT as apposed to New Zealand, and they are a sponsor. If you would like to demo either of the WM's sizes, they are available from WFF.
Thanks for the feedback. Both manufacturers stated that their material is stronger. Does anyone have any objective or scientific information on which is really stronger. Waterstrider is a urethane/pvc alloy. Watermaster is PVC. (I think) Waterstrider is considerably lighter in weight which would make one think it wasn't as durable, but maybe the alloy material is better. I don't know.
At the time I compared the two, I found the oarlocks on the Watermaster Kodiak were in a better position for rowing for me (6'1", 240) than those on the Waterstrider. That tipped the balance toward the Kodiak for me even though the PVC version was a bit heavier and a bit more money. I really like it. I really liked the urethane version of the Kodiak, which I don't see on their website anymore, that a friend has as it was lighter than the Waterstrider but a bit too much for my wallet.