In today's world of excess baggage fees and rough baggage handling, you just can't be too careful when it comes to packing your photo equipment for dive travel, and while you don't want to leave anything important at home, you've also got to strike a fine balance between packing a little more than bare essentials and finding yourself without a useful piece of gear. Here are some tips to help you next time you're packing for a diving vacation. A quick caveat: Airline rules, regulations, and fees can change quickly. Check with the FAA and other authorities, and check with your airline to see what is and is not acceptable practice.
Checked Baggage
If cost is no object, pack as much as you want and pay for overweight luggage fees with a happy grin on your face. Or, upgrade to business or first class, both of which tend to offer more liberal luggage allowances.
If cost is a concern, then thin out the contents of your checked baggage to reduce the weight. For tropical destinations, clothing can be kept to a minimum most of the time, and even at cooler destinations, laundry service can be had for a small fee so packing a lot of clothing might not be in your best interest. Unless you'll be roughing it or staying on a liveaboard, shampoo, soap, and toothpaste can often be kept to a minimum too. Even then, it might be cheaper to buy what you need when you arrive than it would be to pay to have it flown across an ocean or two.
This strategy is important because it saves room for underwater photography gear. If you're still planning to buy this gear, and you know you're going to be traveling a lot, look for compact and lightweight options. These are getting to be less expensive and easier to find than they once were. If you're packing liquids and equipment in the same bag, put everything in watertight bags and check, double check, and triple check to be sure it's all sealed up.
Carry On Luggage
Carry your most expensive items with you. Laptops, cameras inside their housings, external hard drives, and other electronics shouldn't be left to the mercy of the airlines. If you've got a lot of expensive gear, consider buying and wearing a photographer's vest to fly in. While it's not the most stylish thing you could wear, it keeps everything safe. Expect to be thoroughly investigated by security personnel if you follow this strategy, and remember to be good-natured as they talk with you about what you're bringing on board. In most cases, they've seen people try all kinds of shenanigans and they're usually quite understanding and accommodating when passengers work with them.
Finally, remember never to travel with all your images stored in just one place or on just one device. Use the cloud if possible - upload your photos before you leave for home, and they'll be safe when you arrive, even if something is lost or damaged. Since most world destinations now offer internet connectivity, this is easier than ever.