Rapids - how to let dogs swim in a lake or river without them running off?

how to let dogs swim in a lake or river without them running off?

I want to let my dogs swim in the river near the house. how do I prevent them from swimming to the opposite shore and escaping

Wow, I have labs that wouldn't dream of running off. They'd never leave me since they know I feed them LOL! I'd suggest formal training to ensure that the dog will come back to you when called. A whistle plus food reward can teach them to come back to you. But, if you have a dog that's prone to being highly independent being off lead is a problem. You could use a long lightweight "leash". I'd make sure they swim in a spot that's free of debri so the leash doesn't catch. If it did catch? You better be prepared to dive in to keep the swimming safe for the dog. Don't use this method at once because handling two dogs with two long leads in water could easily entangle the leads.
use a long leash
Get going with the solid recall! And be careful about lakes and rivers - lakes especially as often, at certain times of the year, they contain algae, which can be extremely toxic to dogs.
ummm...obedience training?