I shouldn't just give this away, bat as far as day boats go, here is what we say in The Scuba Snobs' Guide to Diving Etiquette, Book 1, edited for brevity here. There is a bunch more in Book 2.
Chapter 3
Rules Of Etiquette On The Day Boat
Most diving is done from boats that leave from the dock and return on the same day. These are day boats (or night boats, if taken for a night dive). Some are very small and offer no amenities. Others are large, equipped for 24 divers or more with multiple tanks for each diver. These boats often offer beverages, snacks, and sometimes even a real lunch. They usually have a head (toilet). To be a proper diver on a day boat, you must follow these rules of etiquette:
USE A BOAT BAG
This is the primary rule of etiquette for day boat diving. It cannot be over emphasized. For those who dont know, a boat bag is a soft mesh duffle bag that can be collapsed to the size of a shoebox or smaller. It will hold all your gear, and it will not be in the way on the boat. Get one. Use one....
There are thousands of scuba retailers who will be very happy to sell you one.
The flip side of this point is that having no bag at all is only slightly better than having the big inappropriate gear bag or suitcase or chest. The diver who has his/her hands full of gear, lunch, and other stuff and drops things all the way down the dock, or (worse still) on the boat and on our feet, is also being inconsiderate and is not our friend. Get a boat bag. They are cheap.
LISTEN TO THE BRIEFING
It doesnt matter if you dove the site yesterday, or dozens of times, or that you know the divemasters name. On every dive, please shut up and listen to the divemasters (and if applicable, the captains) briefing. Conditions change, not everyone on the dive was along yesterday, and we need to hear the briefing. So do you. We do not need to hear your summary of yesterdays dive. The divemaster does not need your help. Give your monologue a rest for a few minutes already. This is an important rule. ...
To listen to the briefing means you are not doing anything else during the briefing. You are not talking to other people, you are not taking a picture, and you are not still screwing around trying to figure out how to set up your gear. You are not fiddling with your camera or video. Do those things when everyone else is doing them. If you need help with your gear, ask the boat crew or dive leader,....
KEEP YOUR STUFF OUT OF THE CAMERA BUCKET/WASH
Most but not all day boats will have a large bucket or barrel filled with fresh water into which cameras
and nothing else are placed. These camera buckets give expensive photo and video equipment a safe ride and keep them out of everyones way while on board. The camera bucket is not for you to dip your mask in, or to wash off your regulator or your computer or buoyancy vest or anything else. If you listened to the briefing you would know that. ...
DONT SMOKE
Here is a simple rule: No smoking. No smoking of anything, at all. Dont even bring smoking materials on board,... No one wants your smoke destroying the wonderful aroma of the salt air, and if you flick your butt into the ocean, you should be banned from all dive boats forever. Liveaboards (see Chapter 4) may have a place for you to engage in your habits, but day boats dont. ...
PUKE ONLY WHERE APPROPRIATE
Never puke on another diver. Never puke on the boat. Dont puke in the camera bucket either. Puke over the side of the boat. Thats about all there is to it. Fish love puke, other divers do not. Also, try not to be too obvious when you puke. Dennis quite often pukes at the end of a dive. But he can be so subtle that on occasion even Debbie, who is sitting and gearing up right next to him, has to ask if he in fact puked. Its a gift.
PEE ONLY WHERE AND WHEN APPROPRIATE
The jury is in. The debate is over. It is ok to pee in your wetsuit when in the ocean. It is okay to climb back on the boat if you wait at least five minutes after peeing in your wetsuit in the ocean before re-boarding. It is not ok to pee in your wetsuit when on the boat. If you are on the boat and have to pee, and there is no head (toilet) on the boat, either hold it or jump in the water and pee. This works best if the boat is not moving and if you tell at least one other person, preferably a crew member, that you are jumping in for a minute. Once you have finished, wait five minutes and then re-board. Guys, it is
not ok to lean over the gunwale, pull it out, and let fly. Ever. This is not ok for the ladies either, just in case you were wondering.
DONT KICK, JOSTLE OR HIT OTHER DIVERS
This is a rule you might think doesnt need to be included here, but remember some day boats are quite small. On them entry into the water is usually done by everyone counting three and rolling backward at the same time. The point is to do this simultaneously but
without kicking the diver next to you. ... Here is how to avoid kicking the next person on the back roll simultaneous entry:
1. Before you roll off, check your position, check the divers to your left and right.
2. If you are crowded ask nicely for a little space
3. Move out of other divers space
4. Go at the same time as everyone else. That means get your stuff together and be ready to go when the dive master says go.
5. Just roll backwards. Dont push off or lunge. Just fall in by leaning backward and straightening your legs
6. When you feel wet move directly away from the boat
Some people also kick, hit or jostle other people getting on and off the day boat, or moving around it. They kick, fall onto, elbow, head butt, or make other avoidable physical contact. They are often late to arrive, late gearing up, ... and they usually dont have a boat bag. They move around cramped quarters oblivious to everyone elses comfort. On the day boat, move slowly and deliberately. Hold onto something to keep from slipping or falling. Dont elbow past people. If you need someone to move, politely ask them to move. Its just good manners. You are not the only person on the boat. ....
TALK ONLY WHEN APPROPRIATE AND LIMIT YOURSELF TO PROPER CONTENT
On the day boat, it is ok to introduce yourself to other divers and ask where they are from. Polite greetings and exchanges are appropriate. If you lack a dive buddy, it is appropriate to ask others on the boat if they have a buddy and, if not, if they will buddy with you. But dont be a pest about it. ...
After a dive, it is appropriate to share with others all the cool stuff you saw. Thats why we all dive. It is also ok to report any symptoms of decompression sickness or other injury or problems. In fact, always do that. Polite, pleasant and positive conversation is always appropriate. Other stuff is not. Here is a list of conversation
donts:
*
Dont bitch at anyone on the boat, including your dive buddy, even if you are married to them.
*
Dont bitch to or about anyone on the boat crew
* Dont bitch about the weather, the visibility, currents, or anything else beyond the control of the people you paid to take your diving today.
* Dont use profanity at us or anyone else. Its bad manners.
* Dont tell everyone how your last dive here or elsewhere was so much better than this dive.
* Dont talk so loud that people not in your conversation end up being a part of it.
* Dont offer unsolicited advice to any other diver unless you are a licensed and insured divemaster or instructor and see the other person doing something dangerous and wrong. You have no doubt been on the boat with the person who has maybe 10 dives but cant stop telling people what to do and how to do it. And they are usually wrong. If someone asks you a question, and you are competent to answer or assist, then ok. But it might be more appropriate to direct them to a professional on board, preferably one who is being paid to work this particular dive outing.
Dont criticize other divers. A Scuba Snob is allowed to criticize other divers, but really only does so on rare occasions. We prefer to talk about them after we have escaped from their presence. We hear husbands and wives speaking critically to each other before and after dives. Sometimes a parent will yell at or be critical of a child. Sometimes its a future ex-boyfriend criticizing his for-the-moment girlfriend. When any of this happens, it can totally suck all the positive energy off of the boat, and even out of the surrounding ocean. One of the reasons we love diving is that the people are almost always fun. We can share the diving experience together, and its all good. Until someone goes negative. Dont be that person.
PLEASE TIP
Do it. Tip something. Tip in local currency if you can. Always tip in cash. If you are clueless as to what is appropriate, then tip five to ten dollars per tank per diver. Thats a fair range. The tip can be on the lower end if the services provided are minimal, more if someone set up your gear for you, changed out your tank, gave you a beverage and/or snack and/or lunch. You should tip more if the divemaster retrieved the piece of gear you dropped overboard, or saved your life, or did something else special like that. Some boats have a tip jar. We make a habit of asking if there is one, and usually ask loud enough so other people will hear us ask and hopefully tip. If there is a tip jar, put your entire tip in it. If there is none, tip the divemaster and captain separately. Also, tip every day since the crew and dive masters may change daily. ...