Persons in the Water (PIW)

Have you ever heard the abbreviation “PIW” used on the marine VHF Radio? It stands for “Person(s) in the Water.” It is a commonly used Coast Guard abbreviation.  During an emergency or distress situation, it is important for the Coast Guard to know the number of persons in the water in order to make an accurate assessment of what is happening on the scene.

You may have a PIW due to a fall overboard or a collision. In those cases, the person in the water is an unexpected event. Conversely, you may have a PIW that you put there intentionally. Asking a passenger or crewmember to go into the water is the topic for today.

You might find it necessary to go into the water in order to assist with getting your vessel afloat after going aground. You may need to remove a line or some other debris from your prop. You may even want to go into the water to retrieve someone or something that has fallen overboard.

Keep in mind that when you are on your boat, you are generally not in an area that is designated for swimming. The waterway has not been evaluated for hazards to persons in the water, and is almost never monitored by lifesaving personnel. There are some risks that you assume when going into the water in such an area.

There are several things to think about before going into the water in the vicinity of your boat. First and foremost, there may be other boat traffic in the area. Other considerations are the water temperature, bottom conditions and currents, just to name a few.

When you are in the water, a wake from a passing boat may move your boat abruptly while you are below with a snorkel untangling a line. If you need to go below, instruct someone above to use a “warning signal,” such as loud tapping on the hull, to alert you to any impending danger.

If the water temperature is cold, beware of the effects of hypothermia. Remember, any temperature below your body temperature will lower your “core” body temperature. The lower the water temperature is, the higher the risk if hypothermia. If hypothermia occurs, even if you remain conscious, you may not have the strength to swim to your boat or climb back into it.

Bottom conditions can vary (sand, mud, rock, etc.). There is always the chance of debris that can injure you. It is wise to use some kind of footwear and clothing that will cover you if the conditions are not known. Also, a very soft muddy bottom may cause you to sink knee deep. If you fall forward or backward in those conditions, you may not be able to get up, subjecting you to drowning.

A strong current can also lead to trouble. The obvious concern is that it may carry you away from your boat. If it is after dark, and if you are swept into a navigable channel, oncoming boat traffic presents a hazard. A person in the water is not very visible after dark.

If you find it necessary to go into the water, consider all of the “unintended consequences” that may present themselves. Good old fashion common sense usually prevents such consequences!

Until next time, we wish you clear skies, fair winds and calm seas!


World Wide Marine Training, LLC, is a U.S. Coast Guard Approved facility authorized to give examinations for captain’s licenses up to Master 200 Tons, Able Seaman up to Unlimited, STCW Basic Training, Radar, ARPA and other Endorsements. Please visit or call toll-free 866-249-2135.