Ever had a piece of gear fail you at the worst possible moment? For divers, a dead underwater scooter at 80 feet with current pushing sideways turns a great dive into a survival situation. This episode breaks down what actually matters when choosing a dive propulsion vehicle, from battery chemistry to trim characteristics, based on real-world testing across six continents. Whether you're a technical diver planning wreck penetrations or a recreational diver looking for something you can actually get on an airplane, Marcus Okafor shares the hard-won lessons that separate reliable scooters from expensive disappointments.

• Lithium-ion batteries outperform lead-acid in ways that matter underwater. Think of it like comparing a fresh flashlight to one with dying batteries—lead-acid scooters lose up to 40 percent of their power before they'r ...