My golden retriever took to the water on his own the first time I took him to the beach...my other dog a samoyed mix, stayed at the edge of the beach watching until we were leaving, then she went in and loved it. The GSD puppy doesn't like streams, creeks, and ignores the ponds, but when you turn the shower on she sounds like a horse trying to get to the water...I figure that they will eventually like it or they won't, but I wouldn't force them. I will try the kiddie pool with the GSD this summer and I think that is the best way to start.
Misty- Samoyed Mix, Tannor- Golden Retriever CGC
Robyn- GSD CGC, TC, Midnite-GSD CGC,TC, Brennan-Golden Retriever CGC, Batman-Husky/Greyhound , Apollo-GSD