I went to Big Bear Lake last week for 4 days, because I wanted to take my boy out to nature AND to teach him how to swim. My dogs before him were a dalmatian, a corgi and a golden, I was still living my parents who had a pool so they were all good swimmers, plus their breeds are indeed water dogs. Correct me if I am wrong, but GSDs are not water breed.
Initially I brought him twice to a dog beach. He ran and ran at the beach but as soon as the wave comes in, he avoided it at all costs. Won't even retrieve his ball. So I put a harness on him and took him with me further in the water, to teach him how to swim. Although he was paddling, he didn't enjoy it and he was paddling JUST to get out of the water.
So I decided to take him to Big Bear lake. That day there was barely anyone but me, my sister, and my dog. He was so happy and so excited to be running around at the fake beach/lake, I have never seen him so happy and free! I started throwing sticks and tennis ball into the shallow water (there was no waves, just the wind blowing the water). He hesitated as first, but then we encourage him so much that he finally retrieved the sticks/ball. Spent 2 hours there, by the time we were gonna leave, he was able to swam ALLLLL THE WAY TO THE MIDDLE of the lake confidently! No hesitation!
And I tell you this: I swam a little to the middle, pretended to drown and shouting 'Help! Help!' and calling his name, he barked and panicked like crazy at the beach pacing around, and then FINALLY he swam alllll the way up to me! And I held on to him while I he brought me back to shore!
I couldn't be prouder. HE couldn't be prouder of himself. It was the best day.
I think that with dogs who don't naturally just like water from the 1st moment, teach him how to swim, how rewarding swimming is, build his confidence! That's all they need; confidence.