Oceanographic fieldwork has traditionally meant going to sea on a ship. In recent years, it has expanded to include activities that may require a ship for a short period but then continue independently. Floats that drift with ocean currents, periodically reporting their positions via satellite, for example, are generally launched from ships but do most of their work independently. Long-term seafloor observatories may need ships to set them up and service them occasionally, but, again, they are designed to collect data for long periods without needing a ship. We have come to think of the body of ways oceanographers glean information from the ocean as “access to the sea,” and so that is the topic for this issue of Oceanus.