This woman is paddle boarding in Dana Point Harbor and you can see the whole setup here in a view from the pier. She has the leash attached which some don't use but she also doesn't have a safety vest so probably a good idea.
The only thing to worry about is sharks as they have bitten a few paddleboards this year when the paddlers got too close to their feeding areas. No person bitten so far this year in our southern California.
Last year in May a Marine helicopter warned Dana Point paddleboarders, "You are paddleboarding next to 15 Great White Sharks, exit the water immediately". That was last year.