a man snorkeling in bright blue water
a man snorkeling in bright blue water

Swimming & Snorkeling

Swimming & Diving Near Boats

There’s nothing like swimming from the back of your boat on a hot summer day. But swimming from your boat isn’t nearly as predicable as swimming in your pool. Boats may anchor in deep water and then, seconds later--a puff of wind or current-- and the terrain beneath the boat is altogether different. There may be rocks lurking just below the surface, currents that can carry a swimmer away, or boats that come too close.

To make sure you and your crew stay safe while swimming from your boat, there are a few things you need to know

  • Swimming from your boat can be great, but there’s a time and place for it. Never, ever swim in a marked channel, even if there are no boats around. You never know when a boat with limited maneuvering abilities will come along.
  • Swimming in marinas should also be avoided. Marinas are made for boats to come and go; they are no place for swimmers. In addition to the risk being run over, boats that are plugged into AC shore power can sometimes leak electricity into the water, either from the boat or from the marina’s electrical systems, putting swimmers at considerable risk.
  • Illegal dumping of holding tanks also occurs in some marinas, further making them unpleasant swimming holes.
  • Don’t swim in areas where there are strong currents or undertow.
  • Enter the water gradually, never dive. Under a boat, the terrain can be uneven, and landing on a rock or shallow spot is a real risk. Even if you’re going back to a familiar spot, droughts and currents can change bottom characteristics.
  • Never leave the boat’s engine running while swimmers are in the water. Propellers can be deadly, and so can carbon monoxide (CO) fumes. Even a running generator can cause CO fumes to accumulate near the boat, which can be fatal to swimmers.
  • When swimming from a boat, wear a life jacket for flotation or have flotation devices in the water for easy access by swimmers. Running a line off the back of your boat with a flotation ring or throwable float can also be useful.
  • Make sure if you get off the boat, there’s an easy way to get back on. Not all boats are easy on, easy off.

Swim-proofing Your Swim Platform

a number of people playing in the water behind a large yacht

If you have a swim platform, take a look at the cleats or other hardware attached to it that could cause injury if a person slips and falls on it.

There are several things you can do to make swimming from a platform - molded or teak - safer.

First, you can improve the non-skid by using a nonskid tape, which is inexpensive and much safer than the molded-in patterns. You can consider moving the cleats (or having a professional do the job) so that they are out of harm’s way.

It might also be possible to install a pop-up cleat that folds out of the way when it’s not being used. As an alternative, you could improvise a cover using something like a sailboat spreader boot or old tennis balls - anything that might soften the edges of the cleat, should a swimmer fall.

Other Activities

Snorkeling is great fun, but it’s easy to get so engaged in looking below the surface that you forget to look above! Many of the above swimming rules apply to snorkeling, but with a little extra caution thrown it.

  • Practice snorkeling in a pool first. Breathing through a tube may seem easy, but for some people it takes some practice. It’s easy to become flustered or fatigued when you are in the ocean and confused about your equipment.
  • Snorkeling can be very distracting, so snorkelers must make an effort to look up every few moments to gauge their position and make sure they haven’t strayed too far from the boat, or into a channel.
  • In popular snorkeling spots, there can be a lot of boats coming and going. Wear bright colors, or better yet a bright life jacket or snorkeling vest to make yourself more visible.

Scuba Diving is also a popular sport which requires significant skill and attention to safety. Two of the most essential pieces of equipment for divers, aside from their diving gear, are two identifying flags: the blue and white Alpha flag and red and white diver down flag.

Other Activities

a white and blue alpha flag

The Alpha flag signifies restricted ability to maneuver and must be flown from the boat hosting divers or snorkelers. This is the only flag that is required by federal law to be flown by boats mothering diver or snorkelers, and a rigid replica of it no less than 1 meter (3.3 feet) high must visible to other boats. At night, red over white over red 360 degree lights must be displayed.

a red and white diver down flag

The second flag, called the Diver Down flag, is probably more recognizable to most boaters. This flag is flown from a float in the water where people are engaged in diving activities.

It is not required by federal law to be displayed, however some states do require it. This flag will help other boaters know there are divers beneath the water who could immerge at any time.

Other boats that see these flags displayed should give the area a wide berth. Laws vary from state to state on how much distance a boater must give an Alpha flag or diver down flag; in some states it could be 300 feet, in others 100 feet. While boating anywhere near a diver down flag, keep a lookout for bubbles breaking the surface which could indicate divers who have strayed away from their boat.

a chart of boat lengths and approximate max capacities