Get my water bells & fins here: https://www.hydrorevolution.com/bj-gaddour-aquatic-fitness-and-training/

This is the 3-Way Biceps Blaster Ladder!

Do 1 overhand curl, 1 underhand curl and 1 hammer curl. Then do 2 + 2 + 2, 3 + 3 + 3 and so forth. Try to ladder up to 5-10 total reps. For an extra challenge, ladder back down to 1.

Overhand curls work the forearms more. Underhand curls target the biceps. And hammer curls hit the brachialis.

You can also take dumbbells into the pool for a mix of weight plus constant tension fluid resistance. Or use water bells for pure drag resistance.