Even the most aquatically capable individuals can only descend into the sea for a few minutes at best without the aid of technology. To study the sea requires that we observe it through a variety of means over protracted periods of time. Some of the ways we do this are by carrying our own Self-Contained Underwater Breathing Apparatus (SCUBA) or having air pumped down via a hose, using unmanned tethered vehicles that are towed behind a vessel to photograph or sense the seafloor and water column, riding in piloted manned submersibles, or by programming autonomous underwater vehicles.