No boat is truly unsinkable, but Sea Hunt builds its boats with flotation in mind. Every Sea Hunt has closed-cell urethane foam filled into the compartments around its fiberglass stringer grid, which adds buoyancy and helps the boat stay afloat. That foam, along with the all-fiberglass, rot-free construction, gives a Sea Hunt a solid, safe feel on the water. Still, most Sea Hunt models are over 20 feet, so they are not required to have full Coast Guard level flotation the way small boats are. So while a Sea Hunt is built with real safety in mind, you should not count on any boat being unsinkable.