1. Stuck up divers with big egos who think they know everything.
Divers like this tend to be less experienced. More experienced divers know that you never stop learning.
2. When someone puts the cap back on an empty tank and you accidentally gear up with it.
It’s not good to completely empty a tank – the lack of pressure makes it easier for water or other contaminants to get inside when the valve is opened, and temperature changes can actually cause negative pressure inside so that it sucks things up. Try to leave a little pressure in there.
3. Throwing/slinging gear when other people are nearby or scattering them everywhere, which leads to things like tripping on or jamming toes on a tank (or having one fall on and shatter a foot).
If the safety of others doesn’t motivate you to avoid the above, then perhaps avoiding damage to your expensive gear will?
4. Divers who hold up the rest of the group or return late
On the flipside, impatient or micro-managing guides/crew who rush or restrict things too much are just as annoying.
5. Parents who insist their uncertified-but-trained child should be allowed to break the rules and participate in a dive tour.
Letting your uncertified child dive during private family trips is nobody’s business, but if a guided dive trip requires attendees to be certified and your child isn’t then you have no business arguing with them.
6. Certified divers who can’t swim
Yes technically it’s possible to scuba dive and snorkel without knowing how to swim, but knowing how to swim might just end up being useful one day – or save your life.
7. Kicking up silt and ruining visibility for everyone
Often caused by speeding, which also scares off wildlife before others get a chance to see them. Poor visibility can also be caused by environmental conditions – visibility tends to be worse in summer because of increased bacterial/algal/biological growth. Visibility also tends to be better in the morning as the waters are calmer and debris tend to have settled overnight.
8. Damaging reefs, harming wildlife or stealing wreckage
It’s best to keep your hands from anything – depending on local laws it can actually be illegal to touch any of the above. Keep all your equipment and and accessories secure and tidy as well so that they don’t accidentally contact the environment in a destructive manner. Chemicals matter too – check that things like sunblock and cosmetics you’re using aren’t harmful to the environment.
9. Getting kicked in the face by the diver in front of you
Sometimes it’s at least partly your fault for tailgating.
10. People wearing their masks on their forehead
It’s supposed to be an SOS signal (not to mention an increased risk of it falling off).
11. Smoking around other divers on a boat
Apart from negatively affecting your diving performance and increasing the risk of decompression sickness (as well worse symptoms when it does occur), there are places that will refuse you if you are a smoker.
12. Snobbery with equipment, agencies, techniques, etc.
Tip: open water courses are cross-recognized by all agencies, so it’s possible to take an advanced course at a different agency from the one you got your OW certificate from.
13. Tour bait-and-switches
A booked diving trip that ends up being completely different to what was advertised can sometimes be an honest mistake or something completely out of the operator’s control, so search for reviews online to see if it is a common occurrence and to try to get both sides of a story for bad reviews.
14. People putting their hands on your gear without permission
Applies both above and under water, even if it’s to provide (unwanted) help.
15. Strangers who rant or ask questions about off-topic/personal/controversial topics during a dive trip
Some people even try to sell you stuff.
16. Boats that ignore your dive flag and run or stop above you
This has and is becoming illegal in many places (beginning in 2014 in Florida for example). Speaking of Florida law, boat diving specifically requires a diving flag while boat-less divers may use safety sausages/buoys instead.
17. Making too much noise underwater
Especially excessive banging of tanks. Studies have found that even small human-made noises made on or under water interferes with animals’ communication and navigation. It also attracts sharks.
18. Good weather that turns bad as soon as you free up some time
Actually, watching and listening to raindrops from underwater makes for a unique and wonderful aural and visual experience – rain-diving is fine as long as there’s no lightning.
19. Rental gear that’s in poor condition (or even worse, dangerously dysfunctional)
BYO gear may seem like a hassle especially if you’re going halfway across the world, but it can be worth it for the peace of mind (assuming they’re well maintained) and hygiene.
20. People who don’t listen to briefings
You could end up breaking rules, breaking laws or breaking something in your body (including your life).
21. All the preparation and cleanup that has to be done before and after a dive
But it’s all oh so worth it in the end.
22. Walking around a boat with fins on
Apart from annoying others and usually being against rules, you could also trip and fall (and if it’s into the water without being prepared, fatally).
23. Shining lights into people’s faces
Even if you don’t do this, excessively bright or numerous lights can also be annoying. But brighter is better for safety and visibility, which is where adjustable ones come in.
24. Getting thirsty in the middle of a dive because you forgot to hydrate before
Fortunately there are ways to drink underwater (no, not alcohol) but whatever setup you use to hydrate yourself with, drink in quick short gulps with plenty of time to breathe in between so that you minimize the time spent holding your breath – and don’t drink anything while ascending. Water itself doesn’t compress much so any beverage you take underwater won’t change much in volume so you don’t have to worry about that.
25. A freshly filled tank that ends up sitting unused because life gets in the way
The air in a tank can be usable for a very long time assuming it was and has been stored in good condition (especially away from heat) and was properly filled from a good source (without moisture or other contaminants) – people have used filled tanks that have been left unused for decades! If you have doubts about a long-stored tank perhaps give it a little sniff of the air inside if anything smells off. If water got inside it could have rusted and used up some of the air (which is how it could go “stale” or “bad”) and weakened the tank too. Storing a filled tank in or near a hot area (like the inside of a car in summer) will increase the pressure inside and can cause its pressure safety disc to rupture or valve components to deform and lose all its air. It can also weaken and reduce the lifespan of the tank itself.
26. Freedivers who can dive deeper than you with scuba gear
Note that sharing compressed air with a freediver at depth can be dangerous if the freediver ascends while holding their breath like they would normally do as the pressurized air in their lungs will expand and injure or possibly kill them.
27. When you and your long-time dive buddy are forcibly assigned a third stranger to dive with
A 3-person diving team has both advantages and disadvantages over 2 – if one diver encounters trouble there are two sets of helping hands and more spare air/equipment, but it also means you each have to watch two other people and good communication becomes that much more important (which of course is more difficult with strangers). 4 or more people is simply too cumbersome and usually splits.
28. Local dive shops underfilling your tank and/or charging too much for air
This isn’t necessarily because the shop is cheap but because a full tank that cools will drop in pressure and the process of filling it heats it up. Also for beginners who might be tempted to do this you can’t use any old non-scuba compressor lying around to fill a diving tank: first, most home-use compressors don’t output nearly enough pressure (100-200 psi vs 2000-4000+ required, the latter costing thousands of dollars) and secondly many use oil to lubricate which will get inside the tank and can be fatal if and when you breathe it in. If you only dive occasionally it may not even be worth buying your own tank.
29. Contact lenses falling off underwater
If you wear glasses, you can get prescription masks or off-the-shelf insertable lenses for some models, though they aren’t cheap. If you don’t require much correction then even those may not be necessary as simply being underwater magnifies everything.
30. When you take a hiking compass and end up flooding it because it isn’t waterproof
Dive compasses should be used instead – even if an ordinary compass doesn’t flood right away it’s typically not designed to be as resistant to corrosion in water, and they also have a poorer tilt range.
31. When you tumble-dry a diving suit and it melts
Turn the heat off when tumble-drying one.
32. Diving suits that fit perfectly except for one part of your body
It’s possible to tailor your diving suit to adjust it for your body (for example if you have long limbs or a short torso) – you’ll need to use neoprene contact cement and/or stitching that stretches. Dying your suit on the other hand doesn’t work so well – it won’t stay on and instead will stain your body and pollute the environment.
33. The fact that you can’t enjoy alcohol before diving
You should never DUI (dive under influence), but drinking after you surface can also be dangerous by mimicking/masking symptoms of decompression illness and also causing unpredictable effects (dehydration being one cause).
34. When one ear just won’t equalize
If all the usual tips fail (wiggling your jaw sideways, tilting your head back, swallowing, etc.) don’t try to force anything – it could be something out of your immediate control like physiology (which could be fixed with surgery), colds/allergies, earwax or some other obstruction or deformation. Note that if this is happening on land, it might clear just fine underwater from the pressure.
35. Not being able to dive because of a broken bone
If you do dive with a fracture, air bubbles can form at the fracture site and prevent/delay healing (or worse).
36. When you aren’t allowed to carry-on your regulator on a flight
This can and does happen, so be prepared to leave some space/weight in your checked luggage in case you have to put it in there – just make sure it’s surrounded by soft items like clothes/towels etc. to reduce the risk of damage and theft. Don’t worry about low flight air pressure damaging it – all storage compartments are pressurized.
37. When your local dive spot is closed so you come back home and practice in your backyard pool
Beware that practicing in a swimming pool isn’t completely hazard-free. While it’s virtually impossible to get the bends in a pool, you can still injure your lungs from barotrauma since most air expansion occurs near the surface rather than at deep depths. Pinched nerves and strained muscles are also not uncommon. With regards to equipment chlorine in the pool can contribute to wear and damage, though on the plus side it will also deodorize stinky suits.
38. When your wetsuit is too thick for the weather and you end up having an underwater sauna session
While you’ll hear a lot about the danger of hypothermia in cold waters, less emphasized is the discomfort (and risk of heatstroke) associated with suiting up too thickly in warmer waters.
39. When last year’s diving suit doesn’t fit anymore
Fat loss and/or muscle gain can actually reduce buoyancy by a noticeable amount because fat is less dense than water and floats while muscle is more dense than water and sinks.
40. Stolen valuables on the surface while diving
Get a waterproof bag that’s rated for the depth and time you will be underwater for to keep your valuables with you.
41. Losing or damaging a mask
Which is why some people carry an identical spare mask (especially if they had a hard time finding one that fit). Most mask damage happens while NOT diving and are usually stupid accidents, like stepping on them. Otherwise they can last decades.
42. Losing sight of your buddy or instructor
Wear bright equipment and/or suits so that others can see and keep track of you better (not to mention finding you in case of trouble). You can also initiate the “lost buddy procedure” by looking for them in all directions for 60 seconds then slowly surfacing so that you (hopefully) meet them there.