Scuba Diving Gear: What You Should and Shouldn't Buy
There's no question that scuba diving is an expensive hobby. The expense is on-going too with every dive requiring a fee for the divemaster, the boat, and the tank(s) of air. One question that I think most divers contend with is, me included, is whether it is better to buy or rent. I think the answer depends on the particular item being considered. For example, I don't think anyone but the most enthusiastic diver should buy scuba tanks and that's assuming diving doesn't require a flight somewhere. Here's my take on other scuba diving equipment for warm-water diving.
Things Worth Buying
Wetsuit: A good fitting suit will keep you warm and that's important even in Caribbean waters. Also, owning your own wetsuit also gives you the opportunity to select a pattern or color that makes you more easily identifiable to your dive buddy. I'd probably avoid high-end suits though as the cost to benefit ratio is too high.
Boots and Fins: Comfortable fins and boots will keep your dives enjoyable. Like a wetsuit, you have the opportunity to pick a color or pattern for your fins to help you stand out within a group which your buddy will appreciate.
Mask (and Snorkel): Of all of the items worth buying, a mask is at the top. You want one that fits YOUR face. A leaky mask is very annoying. A snorkel is a nice to have and I've included it here as it's often considered part of a mask even though many divers don't use one.
Mask Defog: A good thing to have in case no one else does.
Replacement Parts: Within my first 25 dives I needed to replace a fin strap. Luckily I had a replacement. Get at least one extra fin strap, mask strap, some O-rings, a handful of zip ties, and snorkel keeper. One thing to confirm is that the replacement parts actually fit your gear. For example, a fin strap might look like it'll fit, but it won't. Go ahead, ask me how I know.
Snips / Knife: Fishing line is common on some sites. While you'll likely be able to signal your divemaster who will have a knife or snips, you'll feel more comfortable having your own. And both a dive knife or snips will last forever
Dive Computer: If you dive multiple times on any given trip, you'll want a dive computer. The main reason is that you can't dive on your own without one -- well you can, but who wants to mess with RDP tables!? So for a place like Bonaire where most of the dives are shore dives you can drive to yourself, you'll need a dive computer to keep you within the safe diving limits.
Dry Bag: I see a lot of divers use plastic bags to keep their clothes or other items dry on a boat. This can fail miserably when there's a lot of spray. I highly recommend getting a dry bag instead of relying on plastic bags -- even zip lock bags will disappoint.
Surface Signaling Devices: I've yet to see a dive shop offer surface signaling devices for rent presumably because the divemaster keeps everyone together and so a signaling device is highly unlikely to be needed. Regardless, I recommend getting one for similar reasons as those for a dive computer. Basically, you'll want one should you ever want to dive your own profile. An inflatable sausage and whistle combination is not that expensive either.
Things That May Be Worth Buying
BCD: From what I know, BCDs will last a long time which makes their amortized cost relatively low. However, they're bulky and they need to be maintained to continue to work correctly. One diver I talked to said she felt comfortable owning her BCD as she became used to it.
Dive Light: I'm averaging 1 night dive for every 10 day dives. I feel that's enough to get a dive light. At around $50 for an LED light which will last forever and rechargeable batteries which will last many years, I feel the cost is justified. And a dive light can be used during the day for peering into crevices and caves.
Slate: If you're diving without a divemaster, a slate could be useful for communicating with a new buddy. Divemasters aren't going to look at your slate and with a regular buddy it'll be quicker to use hand signals you've already become accustomed to.
Underwater Camera: Obviously if you're not interested in taking pictures there's no need to buy a camera. However, if you are interested, you really need to get your own equipment because you need to be proficient with changing settings. You can't be futzing with the menu while the perfect shot swims away.
Fish Identification Card / Book:
If you enjoy knowing what you're looking at, getting your own identification card or book is a must. By the time you get back to the dive shop, there's a good chance you'll have forgotten all of the things you've seen.
Dive Log Book:
Some people enjoy recording what they've seen or what skills they've improved on. My buddy is one such person which is really handy since I can then write articles on this site about the dives I've done. And since I'm busy taking pictures it's good to have someone focused on remembering and recording things.
Things Not Worth Buying
Weights: Every dive shop has enough weights. I see no reason to lug these around with you on planes.
Regulator: Regulators are expensive and they MUST be properly maintained given their life-supporting function. I don't think they're worth buying because of the on-going expense. If you pick a good dive shop, you'll very likely get a good regulator.
Gloves: You won't need gloves to stay warm. You'll lose more heat from other parts of your body. In addition, many countries don't allow gloves as it encourages divers to touch things. In addition, it's harder to adjust your mask or use a camera with gloves on.
Hood: I've yet to use a hood. I don't think they're comfortable and as with gloves, it seems heat is lost elsewhere such that a hood wouldn't make much of a difference.
My dive shop made me purchase a compass. They said it was a requirement of the open water certification course. I'm not sure they weren't making that up. Anyway, I've yet to use a compass and I can't see myself needing one. If the visibility is so poor that I can't see underwater landmarks, I'm not likely to dive.