The pool—or open water (ocean, river, etc.) if you have access—is an ideal venue for a cardiovascular endurance workout. As far as cardio goes, high-effort swimming and water sports like paddleboarding are extremely effective and fun, too.
Exercises: Functional fitness workouts in the water typically call for swimming for distance. Some CrossFit Games workouts do involve paddleboarding. Maybe in the future we’ll see benchmark WODs with other water exercises like kayaking.
Travel: If you’re traveling and staying at a hotel with a pool, swim WODs are a great option because you can get an intense cardiovascular workout in twenty minutes or less. The hotel may not let you bring other equipment to the pool, but you can add in some out-of-water bodyweight movements and do the “Rocket” Hero WOD.
Grab your bathing suit and goggles (and your grit—you’ll need it) and try out a pool/open water WOD for your next workout!