Each dive operation's system may be unique in the details, but all are generally very similar in content. If you took the best ideas from each one, you'd have a complete guide to boat etiquette that would cover everything from safe diving practices to good manners.
On a recent trip to Grand Cayman, I was thinking about dive boat etiquette when I noticed the divemasters at Treasure Island Divers were particularly good at orchestrating the trips unobtrusively and helping divers avoid problems. When I told them I was going to write an article about boat etiquette for novice divers, their response was 'great idea but get the message out to everyone, not just new divers!' Regardless of where you dive and who you dive with, their excellent advice can reduce your worries and increase your fun. Here's what they recommended:
Gear Preparation: Getting your equipment ready before you go to the boat can save a lot of hassles. If you have a new mask, scrub the inside of the skirt and the lenses with toothpaste to remove excess silicone deposited by the manufacturing process. Otherwise, it's going to fog no matter how much you spit into it. If you haven't used your gear in several years, it may have been deteriorating in the closet. Have your regulator serviced and check fin straps and wetsuit seams. Personalizing your equipment can help you locate it among the similar pieces that accumulate in piles on the deck after a dive. Permanently mark your initials on your fins or give your mask a distinctive look with a colorful neoprene strap.
Check In: Showing up at the last minute is guaranteed to make your day more stressful and probably aggravate everyone else on the boat, too. Plan to arrive about 30 minutes before departure, particularly on the first day. This will give you time to park, sign in, unload your gear, check out rental equipment and pick up some water or juice for later.
Get the Lead Out: Lead weights are often dispensed on the boat rather than at the shop. If that's the case, ask a crewmember before you help yourself, because normally the divemaster passes out the weights and belts. Knowing precisely how much weight to request speeds this task, but quite often divers have either forgotten or are using a different wetsuit so they are unsure of the weight they need. One simple way to keep track is to write the number of pounds you use on the inside of your wetsuit, right next to your initials.
For divers who aren't quite sure how much weight they need, Treasure Island Divers suggests a belt with two less pounds than you think you need, plus two pounds in the pocket of your BC. That way you can test your buoyancy as soon as you enter the water and, if you don't need the last two pounds, can easily pass the extra weight back before the dive commences.
Many savvy divers travel with their own belt but use the weights provided by the dive operator. Then you are sure of having the proper fit, plus you can buy a distinctive color that lets you spot your belt among the others quickly.
Setting Up: Getting set up before the boat leaves the dock is a good idea, since it's more stable then and you can still get replacements for broken or forgotten equipment. Most boats have a system for identifying full tanks. Sometimes it depends on which rack the tank is in or which way the valve faces. The most common method uses the dust cap. On means a full tank, off means an empty or low tank. The system usually works well, but don't replace the cap after you use a tank and don't assume your tank with the cap on is actually full; use your regulator to check the air supply.
Two sins that will get the immediate attention of a divemaster are leaving a tank unsecured or a weightbelt on the seat. Store weightbelts on the deck and keep those tank bungee cords fastened! Don't forget to take the bungee off before you try to stand up with the tank, though. It's a common mistake that will earn you the sobriquet 'bench diver.' To avoid this, make sure you don't put your regulator over the bungee and take the bungee off just before you slip into the BC.
In general, the space under your seat is for your gear bag. It's a good idea to make one last check for mask, fins and snorkel but leave them in the bag until you get the word to gear up. The deck always gets wet, so don't leave anything beneath the seat that you want to keep dry. Ask one of the crew to show you the best place for dry items such as clothes, eye glasses and towels.
Gearing Up: Divemasters will often help divers get into their equipment or assist them in walking to the entry point. Some divers may think it reflects on their competence, but it's just a safety measure in case the boat moves unexpectedly. Divemasters watch out for everyone-relax and enjoy the help!
On most boats the practice is to put on your weightbelt and BC at your seat, then stand and carry your mask and fins as you walk to the dive platform. Once there you'll find a convenient place to sit or stand comfortably as you don fins and mask.
Entry and Descent: Before I leave the boat I like to check the position of the sun in relation to the dive site. That way I have a quick visual reference that helps me stay oriented underwater. Of course, a compass will be even more accurate, provided you line up a reference bearing at the beginning of the dive.
Remember, the boat may be moving around a good bit. Let the divemaster steady you and use the railings for support. Don't worry about the dive ladder. It may seem like it's in the way, but a normal giant stride will carry you clear, even if you step straight out over the ladder.
Making a controlled descent along the mooring or anchorline has two advantages: You avoid excess exertion when a current is running and you are in a good place to begin and end the dive on the bottom. As you descend, clear your ears early and often.
Dive Profile: Make the deepest part of your dive first, then work your way toward the surface. Your computer doesn't care if you go up and down repeatedly during the dive, but your body does. Sawtooth profiles can get you into decompression trouble even when your computer and the tables are satisfied. And watch that depth gauge, especially when the water is as clear as in Grand Cayman. At the very least, going deeper than you want will be inconvenient, shortening the bottom time for both you and your buddy.
Slow is Better: On most dives, you'll see more if you swim less. Relax, take it slow or even stop for ten minutes and let the marine life get used to your presence. The difference is amazing!
Surfacing: You have to allow your body to get rid of excess nitrogen, even on a no decompression dive. This normally happens during the ascent, provided you come up slowly enough. The recommended maximum rate of 30 feet per minute is slower than most divers realize. If you're ascending a mooring or anchorline, try going hand over hand at a moderate pace. At 15 feet, make a five minute safety stop. According to the Diver's Alert Network (DAN), a slow ascent is essential in avoiding decompression sickness and a safety stop is excellent insurance.
Getting Back Aboard: Re-boarding the boat can be the most hazardous part of the trip. If your divemasters ask you to do it in a particular manner it's because they know what works best for that boat, so it's a good idea to follow their procedures carefully. Before you remove your fins, make sure you have a good grip on something attached to the boat. In some cases you may be asked to come right to the ladder, but often it's safer to hang onto the drift line that floats behind the boat as you take off your fins. Don't approach the ladder when someone is still on it because they may slip and fall on you or the tank may slip out of his or her BC.
Hand your fins up so the divemaster can grab them by the tips-the water drains out of them more quickly. When you are ready to climb out, put all your weight on the ladder as quickly as possible to lock it firmly in the down position. Keep your mask on and your regulator in your mouth so if you slip it will be no big deal to just drop back into the water.
Here's one last bit of advice from Treasure Island Divers, something you're sure to find universally valid: Don't be afraid to ask! If you aren't sure, didn't hear, can't find, couldn't decide or just don't know, ask the closest divemaster or crewmember.