Boating around buddies
By Ira Barocas, NAUI #10126

Operating a vessel in the proximity of dives is always a challenging and potentially hazardous event that demands the highest levels of seamanship and boat-handling from the operator and crew. Some types of diving, however, would be impossible without the ability to safely launch and recover divers from a free ranging boat.

For instance, many divers enjoy river diving, where an anchored vessel would be miles away from the place the divers eventually wind u (because of surface and bottom currents). Others drift dive in the open ocean, riding currents as if they were nature's underwater sleds, gliding far from their entry point.

Still more diving is done where traditional anchoring is impractical because of underwater obstructions, thick vegetation (like kelp), or the potential for site and environmental damage from anchors. Sometimes a leadership-level diver is used to set an anchor in a difficult spot or retrieve a snagged one.

While all of these diving situations are common. far too many accidents occur when boats manoeuvre around divers. The annual toll of serious injuries and deaths can be greatly reduced of none of these accidents involved our own vessels as opposed to the boating public at large. Forethought, planning, experience, and training can help to avoid potential problems.

Accidents generally happen when a divers is struck by a moving boat, or worse, caught by the spinning shaft and/or propeller(s). All can be deadly-and all can be eliminated since they are nearly always the result of a combination of diver's and helmsperson's errors.

Properly trained divers know that they should surface listening, reaching up, and looking up and around. This should be stressed in the dive briefing. This helps � eliminate the possibility of the boat running over a suddenly surfacing diver or buddy team.

Instructing divers to stay in a group if possible, making the recovery target larger, is highly recommended. So, too, is deploying a surface float that accompanies the divers while they are down, or using a lift bag or inflatable float and/or flag to indicate the diver's ascent area for the boat to approach. Some states and local jurisdictions make it mandatory for divers to surface within proximity of a dive flag-always a good idea!

From the boat operator's standpoint, the two most important considerations are to keep a sharp lookout in the most likely areas, and to keep boat speed appropriate to the conditions. Sometime this means following the divers' bubbles as they progress; at other times it means standing off and watching the water from a safe distance while waiting for divers to sur  face. It may mean drifting along with the surface current or motoring to a pre-determined pick-up area.

It always means careful dive planning and briefing. The boat operator needs to understand the prevailing conditions in the area, how the boat will handle under all circumstances, and particularly, how it won't.

Left to drift, most boats assume a bow down attitude. this means that they will float with the front pointed more or less downwind virtually all the time. this put the prevailing wind and waves on the quarter. As a result, divers should, whenever possible, leave the boat on the windward side of a drifting (engines in neutral) vessel.

Since the boat will drift downwind considerably more quickly than the divers, there ought to be no problem with wave-generated hull suction, nor will there be danger from a moving propeller (since the engines are in neutral).

On some vessels, the shafts and props turn as long as the engines are running, even if they are disengaged. Consider shutting down and lying a-  hull, or arranging an exit point nearer the bow. In any case, be certain that the boat will have time to drift clear of the divers in the water, and direct divers to swim clear. If there's any doubt about the boat drifting away, it's always possible to know where every diver is.

In the ocean, you must consider the surface conditions to conduct these types of dives safely. Moderately high winds, waves, and swell will make launching, spotting, following, and recovering divers much more difficult. This is particularly true when trying to locate divers from a small boat where the operator does not have the advantage of height to make it easier to effectively monitor a greater surface area. Of course, this is mitigated if the water is so clear that you can see the divers below throughout the dive, as in some parts of the world.

While launching and observing the divers' progress is a challenge, recovery is the ultimate test. During this phase of the dive you are not only dealing with maneuvering the vessel in cl  ose quarters to live bodies, but need to get them back aboard with their gear when they may be fatigued. This is sometimes a two-step process, where gear and weight come aboard separately from divers. This is also when a small boat has a real advantage over a larger one. In fact, a larger boat might consider using a dinghy for this task.

Keep in mind that the boat will almost certainly drift more quickly downwind than the divers. The divers, since they are immersed, have less windage (wind profile), and will usually be more subject to the surface current. Bringing the two together is tricky, but it becomes easier with practice.

Since the main goal is to get divers aboard without injury, it's almost mandatory that the engines be in neutral during recovery. If the vessel approaches the divers from the leeward (downwind side) and has heaving lines handy, the divers can use them to pull themselves alongside for boarding and maintain contact with the vessel, even though it is drifting away more rapidly.

If the only boarding point is the stern, the boat is stopped upwind of the divers, floating line go to them, and the divers can pull themselves to the stern as the boat drifts in neutral.

Strong currents present another challenge to the vessel operator attempting to recover divers from the water. The boat will sometimes drift much more quickly than the divers in the water if it as a large keel, is a heavier displacement type, or there is wind in the same direction as the current.

If this is the case, approach dive rs against the current. When they are alongside, put the power to neutral or maintain your position in the flow by careful throttle settings. Make sure that no divers get past the midpoint of the boat, to minimize danger from the drive machinery, and have adequate help aboard to get everyone up as quickly as possible.

You must know your boat, crew, and divers well before attempting this kind of diving activity, and plan and practice your boarding activities to minimize the inherent risks. This is not a sit uation for student divers or unskilled boaters.

After checking current in the nautical publications, and with the benefit of experience, it's possible to make a good guess as to the general area that drifting divers may surface. Some geographic landmark that both the vessel and divers can use, such as a large drain pipe, cable crossing, bridge pier, or the like, makes a good rendezvous. It may then be possible for the boat to get ahead of the divers and anchor downstream to wait. The disadvantage of this is that there's no surface support for divers who may need it surfacing early in this challenging environment.

In any case it's important that divers be positively buoyant at the surface, and that weight belts go up the ladder or into the boat first. If possible, divers should pass scuba units up rather than climb with them if the sea is rough and the boat active.

Each situation and each boat will have some optimal method. It's your responsibility as the operator to have a workable plan and back-up in mind . It might be best, for instance, to make one or two trial runs in the vicinity, or recover a group of divers in pairs, making repeated approaches.

Experience is the best teacher in developing the necessary skills to handle a boat around divers. Practicing stopping, holding position in current, and developing familiarity with a particular vessel's handling characteristics in various conditions of wind and waves should be part of your preparation.

You should, however, supplement that experience with a thoro ugh understanding of the dynamics involved in boat handling and navigation. Many organizations offer these courses either free or for a nominal charge. Examples of these classes are those taught by the United States Coast Guard Auxiliary and the U.S. and Canadian Power Squadrons. There may be others in your area, as well as professional schools that provide not only theory but hand-on experience as well. Marinas, chandleries, local law enforcement agencies, the phone book, and other boaters may also have information on these training opportunities.

Finally, you must practice with your boat at every opportunity and develop confidence in you competence. Use floating buoys and fixed marks. Learn how to handle the boat in every direction. Understand how your boat drifts, how far it will hold way when put in neutral, and how it behaves in wind and wave before using it for diving.

Sources - Second quarter 2007 copyright 1996 NAUI. All rights reserved.

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