it's getting her to stop that's the trick! she only goes paw deep unless I give her some encouragement to swim which is handy as it means she doesn't get too far behind if she does detour into the water, she only really likes swimming to retrieve things, but a stone is enough as she'll go out and have a look for it!
She HATES it if I splash her with water!
the first time I went open water swimming she was off the lead and she followed me in, I'd swum 50m before I realised she was behind me with my wife standing on the bank not quite sure wheter it was funny or worrying!! when I turned round to say hello she freaked out and powered back to the bank and now will just splash about in the shallow water if she comes swimming with me!