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How to Choose a Dive Boat

Before considering a dive boat's schedule and price, you should look at its safety and suitability for diving. And don't forget creature comforts, which assume greater importance at the end of a long day of diving than might seem likely when you made your reservations.

Of course, no one boat will have it all. The skiff that makes a 10-minute hop from the resort to the reef has far different capabilities than an oceangoing vessel that will stay out all day. Provided the smaller boat stays within its capabilities, it can be just as safe, dive ready and fun as a larger one.

Boat Safety

The safety considerations for a trip to the California Channel Islands or the New Jersey wrecks are different from those for a short ride inside the reef. But any boat in water deep enough to drown you must meet certain basic safety requirements. After that come extras.

Your dive boat must have:

  • Fire extinguisher, life jackets and radio. The radio isn't a convenience, but a necessity for emergencies.
  • Coast Guard certification. All boats carrying more than six paying passengers and operating from U.S. ports must be inspected and certified by the U.S. Coast Guard every year. Inspection is rigorous and covers the condition of the hull, machinery and electronics, safety equipment and much more. But rogue operations exist: Ask if the boat has had a recent Coast Guard inspection. Smaller, six-pac vessels are not inspected and are not required to have as much safety equipment. They are not necessarily unsafe, however, particularly for short trips in good weather.
  • Other safety certifications. Foreign-flag vessels operating in foreign waters are naturally subject to foreign rules, if any. Some countries have regulations comparable to the Coast Guard's. The U.N.'s SOLAS ("Safety Of Lives At Sea") Convention applies to nations that sign the convention standards, which are generally similar to Coast Guard standards. But many countries have not signed. Lloyd's Insurance provides another safety and inspection regime. Ask what safety standards the boat meets, and how recently it has been inspected and certified.
  • Licensed captain. At sea, just like under it, experience is the best teacher. The prerequisites for a Coast Guard captain's license reflect that. Before taking the license exam, the captain must have logged many days at sea on a working crew--720 for the common 50-ton license, 360 for a six-passenger license. A license is no guarantee of competence (witness the Exxon Valdez), but it is an essential starting point. All vessels carrying passengers for hire in U.S. waters must be operated by a Coast Guard licensed captain but, again, rogue operations exist. They cannot be insured, so avoid them.
  • Enough crew. The proper number of crew members depends on the size of the vessel, but there should be at least one deckhand. Otherwise, if the captain has to visit the head or deal with an equipment breakdown, who drives? An autopilot does not provide an adequate lookout.
  • Safety briefing. Once underway, the captain or mate should brief everyone on where the life preservers are, and what to do in case of emergency. If there is no briefing, it implies a lack of seriousness about safety.
  • Non-skid decks. Heavy dive gear makes divers top-heavy and especially vulnerable to falling on wet, slippery decks. Look for a heavily-roughed surface, abundant handholds and railings and a minimum of projections to trip on and fall against.

Also nice:

If the dive boat is traveling a significant distance offshore or operating in an area prone to quickly developing weather, you'd also like it to have:

  • Radar. May be the single most important piece of safety equipment, especially where fog is possible.
  • EPIRB. An automatic beacon that sends out a rescue call if the vessel sinks. Any dive boat going offshore should have one.

Dive Readiness

Boats that are either not designed for diving or not extensively modified to accommodate divers make uncomfortable dive platforms. A dive-ready boat has distinctive physical characteristics and procedures:

A dive-ready boat must have:

  • Oxygen. Essential first aid for decompression sickness, an oxygen kit (and training to use it) should be on every dive boat.
  • Assigned divemaster. Someone's first responsibility should be dive safety. The divemaster should know the location and conditions and should be prepared to enter the water if not actually diving with the group. On smaller boats, the captain or mate may do double duty.
  • Pre-dive briefing. You need to be told the depth, current, visability and general configuration of the site in order to plan a safe dive. Demand it, pay attention, and insist other divers keep quiet so you can hear.
  • Diver count system. The boat should have some way of keeping track of every diver. Some boats assign each diver a number and do a roll call before and after each dive. On others, the divemaster checks names off against a list.
  • Current line. The boat should lay out a "current line" or "tag line" even when the current is very weak. The line will be an aid to tired divers returning to the boat.
  • Ascent/descent line. This line controls the descent for divers who have trouble equalizing their ears, and makes slow, controlled ascents and safety stops much easier. The anchor line is often used for this purpose.
  • Ample drinking water. A small jug, hard to get to, with thimble-sized paper cups, does not promote adequate hydration.

Larger boats may also have:

  • Large, organized gear stations. You should be able to keep all your dive gear in one place, where you will put it on. Since you'll never have as much space as you'd like, good organization of the space is important: a vertical mount for the tank that allows you to rig your BC on it; a bench to sit on; storage space under the bench that's designed to keep your bag from sliding out when the boat rolls.
  • Sit-down tank donning. The bench should allow you to sit against the tank, put your arms in the BC and stand up, thus minimizing the strain to your back and the chance of falling while wrestling with the tank.
  • Dive platform below water. Returning to the boat is much easier when the platform is just below water level. It should have hand-holds, and ladders should be wide and sturdy.
  • Multiple exit doors. Exits should be separate from the re-entry point so a diver who needs to reboard the boat to make an adjustment can do so quickly.
  • Freshwater rinse tanks. Separate tanks for cameras and for masks.
  • Camera assembly table. There should be a designated area for handling delicate equipment like cameras.
  • Spear tub. If spearfishing is practiced, all spears should be stored together, away from divers and other gear.
  • Dry storage area. There should be someplace where your clothes and wallet can stay dry.
  • Healthy, varied food. Your energy consumption will be high and food is a necessity. But too many dive boats still think cheeseburgers and chili are fuel. Instead, you need carbohydrates: fruits, vegetables and breads. It's a part of your essential diving equipment, and you should be allowed to bring your own.
  • Extra crew. There should be enough crew to help each diver out of the water and, if necessary, across the deck to the diver's gear station. Sometimes that last 10 feet of deck is the most dangerous part of the dive.

What To Ask Before You Book

  • Is there a dive class on board? We should be tolerant of new divers, but sometimes a certification class dominates the boat, dictating easy dive sites and slowing the pace for everyone.
  • Is solo diving allowed? Practices differ. Some boats will require you to have a buddy and will pair up strangers willy nilly. Other boats couldn't care less.
  • What gear is supplied? Are tanks supplied? Weights? Nothing?
  • What air pressure are the fills? High-pressure tanks don't do you much good when the boat fills only to a hot 2,400 psi.
  • Is nitrox available? It's not yet common, but beginning to appear on the big boats, especially live-aboards.
  • What is not included in the price? Some boats charge for air fills. On others, food is included.
  • Will there be spearfishing? In areas where spearfishing is popular, some boats attract hunters more than others. If you don't like being in the water with spears and blood, find out first who your shipmates will be.

What About Live-aboards?

Live-aboards range from scruffy cattle boats to mini (and not-so-mini) luxury liners. All the considerations that apply to short-range dive boats apply with even greater force to live-aboards:

  • Safety is more important because a live-aboard spends more time at sea and probably goes farther offshore.
  • Dive readiness is more important because you'll probably dive more from a live-aboard than from a shore resort.
  • Comfort is more important because even a big boat is fundamentally a crowded place compared to even a small island. You'll want more pampering.

For Live-aboards, Also Ask These Questions:

  • Has the boat been certified for safety? The boat should meet Coast Guard requirements, SOLAS Convention or Lloyd's Insurance standards. Other boats may not be subject to any safety requirements at all.
  • Is the crew licensed and certified? Does the captain have a Coast Guard (or equivalent) license?
  • What about other crew specialists? "Having licensed mates, engineers and radio operators adds a few hundred dollars to the cost of a trip," says Aggressor Fleet president Wayne Hasson. "But I think it's worth it."
  • Are passengers covered by liability insurance? The presence of substantial insurance coverage is an indication that the boat meets some safety standard because the insurance company will require it.
  • Is there an emergency evacuation plan? Some live-aboards go far offshore, where a medical evacuation will be difficult to arrange quickly unless it has been planned for.
  • Can special diets be accommodated? Allergies can cause life-threatening reactions in divers. Is the cook willing, and able, to meet special needs?
  • How much water? No boat has unlimited fresh water despite advertising claims. Most larger live-aboards have desalination plants to make fresh water. These have a limited daily capacity. What's the capacity-to-passenger ratio?
  • How much space? Any boat is going to seem small after a week. The length of the boat is what's usually advertised, but the displacement (weight of the boat) is a better indication of size: what's the displacement-to-passengers ratio? If you can't find out the displacement, use length times twice the beam (width) instead.
  • How much pampering? The amount of individual attention is directly related to the number of crew members there to give it. What's the crew-to-passengers ratio?
  • How much freedom? Some boats operate on a fixed schedule of group dives led by a divemaster. On others, if the anchor is down and the gate is open, you're on your own. Does the boat's style of diving match yours?

Dive Boat Do's and Don'ts

  • Don't leave open drinks on the camera table.
  • Don't dip masks in the camera rinse tank.
  • Don't forget your C-card.
  • Do remember cash for tips.
  • Don't invade dry areas in a wet exposure suit.
  • Do secure tanks and weights as instructed by crew.

Dive Boat Tip: Be Early . . .

Rushing around builds anxiety while being ahead of the game builds calm. Whichever it is, you'll take it with you into the water.

  • Early to the boat. It may take longer than you think to find the boat, find a parking place, transport all your gear to the boat and stow it. If you're late, the boat may not wait. If it does, you'll be the goat for delaying everybody.
  • Early to dress. Assemble your gear and put on your exposure suit before the boat anchors, if the crew says this is OK. You'll have time to do it slowly and carefully and to deal with last-minute problems. Rushing the gearing-up process invites mistakes. If you're late into the water, you'll be late out of it, causing delay that cascades through the day, upsetting the program for everyone.
  • Early to fill. After your first dive you'll either signal for a refill (for example, by hanging a tag on your tank) or you'll switch to a fresh tank. Do it immediately, before you relax into your surface interval.

Bad Boat Tip-offs

  • Peeling Paint. Should you judge a dive boat by its paint job? Yes, especially where a Coast Guard inspection is not required. If the boat is chipped and scarred and looks run down on the outside, it is probably worn out on the inside too. If the owner can't find the money and time for paint, he's probably not giving first-class maintenance to his diesels and his bilge pumps, either. On the other hand, a trim appearance indicates pride of ownership, attention to detail and financial solvency.

    Is this a generalization? Sure. Just as some cowboys are all hat and no horse, some boats are all show and no go. And by the same token, some captains are fanatical about their engine rooms while they couldn't care less about the torn upholstery in the galley. But without convincing evidence to the contrary, judge by appearances. If the part the customers can see is in serious need of maintenance, chances are the essential but hidden part needs it even more.
  • Shouting. Operations such as leaving the dock and setting the anchor should be accomplished with a minimum of arm waving and screaming. A competent crew needs only a quiet, polite order from a competent captain. Shouting is an attempt to rectify inadequate training and poor communication, and always fails.

Creature Comforts: It's the Little Things

Think the little things are unimportant? Think again. Comfort saves energy that can go into another dive. Besides, you're supposed to be enjoying this.

Obviously, only the largest dive boats can have all of these:

  • Indoor shelter. Normally this is the galley area, and normally it's a "wet" area, so you can use it between dives.
  • Bunks. If you need to stretch out and nap, there should be a place to do it. Normally, it will be below deck, a "dry" area. Are there blankets and pillows?
  • Shade deck. Sundecks are promoted more, but on the water there's rarely a problem getting enough sun. You shouldn't have to go indoors to escape it.
  • Hot tub. Even in the tropics, your biggest energy drain is through loss of body heat. And in cold water, nothing feels better after the last dive than the hot tub.
  • Hot freshwater showers. You'll want to wash off the salt before putting on street clothes.
  • Both wet and dry heads. If you're in dry clothes, you don't want to use a wet toilet area; if you're in your wetsuit, you don't want to have to change.
  • Stability. A wide boat generally rolls less and has a gentler motion. That means less seasickness, less strain from holding on constantly, a better chance of relaxing or sleeping.
  • Speed. Less time in transit means less discomfort, more time to dive.


This subject is surrounded by misinformation because the experts don't understand exactly what causes seasickness. But here are suggestions for dealing with it, based on my 40 years spent in boats:

  • Anyone can become seasick, though some are more susceptible than others. It's not a sign of moral weakness, so don't feel ashamed.
  • All the pills are about the same in effectiveness and side-effects. But if one of them--Dramamine, Bonine, Marazine, etc.--seems to work better for you than the others, stick with it. The placebo effect is very strong with seasickness.
  • Start taking pills early--12 to 24 hours before going to sea. This builds up a level of the drug in your body before you need it.
  • Pills are better prevention than treatment. After you feel queasy, it is too late for pills to help.
  • Scopolamine patches do work better than pills and have fewer side effects (on most people). They are available by doctor's prescription.
  • Some people like "Sea Bands." They are bracelets with dots that purportedly touch acupressure points on your wrists. They have never been proven effective. (Remember the placebo effect.)
  • Bigger is better. Bigger, and especially wider, boats have a slower roll than smaller ones.
  • Stay on deck. It helps to be able to see the horizon, possibly because your eyes then agree with what your middle ears are saying--that your body is rocking and pitching. One theory is that nausea is caused by mixed messages when, below decks, your eyes report that all is stationary.
  • Don't try to read. Focusing your eyes on an apparently stationary target makes them even more convinced that your middle ears are wrong.
  • Close your eyes if you must go below. You may have to go below and lie down, in which case close your eyes so they aren't giving a no-motion message to your brain.
  • Be rested and sober. Even a mild hangover can easily degenerate into seasickness, besides increasing various diving risks. Likewise, fatigue predisposes you to seasickness.
  • Eat something. Opinions vary on this one, but most people feel better with a little bland food in their stomachs. Bread, bagels, pancakes, etc. are better than eggs and bacon. Coffee and orange juice are acidic and may irritate your stomach. Eat a little, not a lot; don't stuff yourself.
  • Anxiety contributes. Those who are frightened by the ocean and the movement of the boat, or anxious about the diving later in the day, are more likely to become seasick.
  • Early signs: chills, headache, frequent burping. Now is the time to go on deck, or move to the lee rail if you're already there.
  • If you feel the urge, let it rip. You'll feel better almost immediately. Prolonging the inevitable only prolongs the pain.
  • Don't use a toilet. Or, God help us, a trash can. Go to the rail on the lee (downwind) side or use a bucket if one is designated. If you feel the urge coming, ask a crew member where to go. He or she will know the best place. Believe me, you're not the first.
  • You'll get over it. Most people feel better in a few hours. For some it takes a day or two. Almost everyone gets over seasickness within three days.

Dive Boat Lingo

  • Forward - Toward the front of the boat.
  • Bow - The front of the boat.
  • Fore-and-aft - Oriented parallel to the length of the boat.
  • Draft - Maximum depth from waterline to bottom of boat; same as smallest amount of water needed to float.
  • Athwartship - Oriented parallel to the width of the boat.
  • Head - Toilet.
  • Port - The left side of the boat.
  • To Board - To go onto the boat.
  • Windward Side - Where wind blows toward the boat. (Don't be sick here.)
  • Starboard - The right side of the boat.
  • Lee Side - Where wind blows away from the boat. (Do be sick here.)
  • Beam - Maximum width of the boat.
  • Bulwarks - Short wall around the top of the hull that helps you stay onboard.
  • Rail - Top of bulwarks, or railing around the boat.
  • Deck - Floor.
  • Bulkhead - Wall running across the boat.
  • Locker - Closet or cabinet.
  • Keel - Lowest part of the hull, running fore-and-aft; the "spine" of the hull.
  • Companionway - Stairs leading into the cabin, or sometimes the doorway.
  • Gear Station - Each diver's on-deck gear storage and dressing area.
  • Aft - Toward the rear.
  • Cleat - Two-eared device for attaching ropes to.
  • Knots - Speed in nautical miles per hour. A nautical mile is 1852 m. Six knots is about seven land miles per hour.
  • Pitch - Fore-and-aft movement of boat such that when the bow rises the stern falls and vice versa.
  • Roll - Sideways movement such that when the starboard rail rises, the port rail falls and vice versa.
  • Yaw - Involuntary turning motion such that when the bow turns to starboard, the stern turns to port, and vice versa.
  • Stern - The rear.
  • Full Whip - Also air whip, air fill. A long hose leading to the boat's compressor, with a fill yoke on the end, so tanks can be filled without moving them from their gear stations.

Click here for a guide to the best shark, sea lion and other big animal dive adventures in San Diego.

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