A safety stop is a 3 to 5 minute stop made between 15 and 20 feet during the final ascent of a dive. Safety stops are required by the majority of scuba training organizations whenever a diver goes deeper than 100 feet or approaches a no-decompression limit. While not strictly necessary, most dive agencies recommend making a safety stop at the end of every dive. Here are several reasons to always preform a safety stop.
• Safety stops increase the conservatism of a dive plan by allowing extra time for absorbed nitrogen to be released from a diver's body. If a diver is close to experiencing a decompression sickness, allowing a few additional minutes for nitrogen release may be the difference between an uneventful dive and a trip to the hyperbaric chamber.
• A safety stop allows a diver to fine tune his buoyancy before ascending through the final 15 feet of water. A diver experiences the greatest pressure change through the last 15 feet of water, which makes controlling buoyancy and the ascent rate more difficult. Allowing time for a last-minute adjustment can help a diver to maintain a safe ascent rate.
• A safety stop provides a short break during the ascent during which divers can check their actual dive statistics against their dive plan to ensure that they have not exceeded any planned dive parameters.
• A safety stop gives a diver a chance to carefully check the surface for boat traffic and other dangers before ascending.