Many travelers wonder if they should bring their own snorkel gear when coming to Hawaii. My advice would be to save space in your luggage and rent instead. It’s like renting a pair of gloves or goggles from a snow shop; it doesn’t need to be the high-end stuff, just as long as the gear does the job.
Renting snorkel equipment (mask, mouthpiece, fins and life vests) can be very affordable and easy to do in Hawaii. Many tour companies provide them free of charge; otherwise, check with your hotel. They may also provide complimentary use of underwater equipment.
If neither falls in your favor, then look for a rental shop, like Snorkel Bob’s or Kona Snorkel Rental. They offer gear rental packages for children and adults that include the mask, mouthpiece, fins, net gear back and t-shirt. However, if all you need are fins and a mask, then perhaps renting ala carte on a “per week” basis may be a cheaper route. Snorkel Bob’s offers basic equipment for $9 a week.
Don’t want to wear glasses or contacts while snorkeling? Ask about prescription lenses for masks (Rx lenses from -1.5 to -10). You pay about $70 extra, but I would say the convenience and comfort are well worth the added costs.
However, if you plan on vacationing in the islands for an extended period of time, then you may just consider buying a cheap set of snorkel gear. Walmart or Longs offers snorkel equipment for less than $15. You could leave them behind for another family to use or bring it back home with you as an island keepsake.