Space.com gives an overview of the training that four astronauts are undergoing over 9 days submerged off the coast of Florida
near Key Largo. The training mission, dubbed NEEMO 18, is one step toward a proposed (mid-2020s) mission to actually visit a captured asteroid in lunar orbit. In addition to the complications of working outside their school-bus sized habitat while awkwardly suited up in a low-gravity (or at least high buoyancy) environment, their mission also includes a 10-minute communications delay, to simulate the high-latency communications with mission control that would be inevitable for an actual asteroid mission.
The experiments astronauts are doing during the mission, which began Monday (July 21), range from the physical to the behavioral. For example, each of the crew members sports a sensor that records how close the crew members work with each other inside the school-bus-size habitat. ... Communications with NEEMO Mission Control is usually constant, and there is the ability to send items to and from the habitat as needed. Also living inside the habitat are two support staff who are assisting with Aquarius maintenance and systems, as required. The crew members also have Internet and phone service to talk with family and friends.