Snorkeling is an underwater activity which needs fairly minimal gear and training. Unlike other types of diving, snorkeling can be undertaken by someone without qualifications, and it is a popular activity in the tropics, where there are numerous interesting things to see underwater. Picking out gear for snorkeling is relatively easy, and many people choose to rent snorkeling gear after their arrival, to avoid having to carry it in their luggage.
The basic components of gear for snorkeling are a snorkel, mask, and fins. In cold climates, snorkelers usually wear wet suits, and some people wear lightweight rash guards in warm climates to avoid sunburn and injuries from coral. A rash guard is a lightweight garment designed to fit under a wetsuit to prevent chafing, but it can also be worn alone as a protective garment. Otherwise, a bathing suit is perfectly fine.
The most important part of gear for snorkeling is the mask. If the mask does not fit properly, it will make the experience very unpleasant. Fortunately, it is easy to check a mask for fit. Start by pulling the strap out of the way, and then placing the mask over your face so that it covers your eyes and nose. If it does not fit comfortably, pick another mask until you find one that does. Next, breath in through your nose to create a vacuum, and pull your hand away. The mask should remain on your face, and if it does not, it is not a good fit. You may have to try on several masks before you find one that works. People with visual impairments may want to consider a prescription snorkeling mask, which will be more expensive, but worth it.
The snorkel typically attaches to the side of the mask. You may want to check the fit of the mouthpiece, or consider purchasing a snorkel that drains excess water off through a sump. Be aware that learning to use a snorkel takes time, and you may want to practice in shallow water before moving out into deeper water. Like other snorkeling equipment, a salesperson can help you with the basics of using a snorkel.
The final aspect of gear for snorkeling is the fins. Fins should be lightweight and flexible, and they come in two basic designs. One fin design slips over the foot like a shoe, while the other has a strap. Fins which strap on are useful, because they can be worn over booties, which will protect the feet from sharp coral and sea animals such as urchins.
When snorkeling, make sure to pay attention to weather warnings and cautions from life guards. You should also be aware of where the shore or boat is at all times, and you should try to snorkel with a companion whenever possible, for extra safety. If you loan out your personal gear for snorkeling, make sure that it fits properly on the person you are lending it to. You may also want to consider taking an underwater camera along, to record some of the amazing sights you will see under the surface of the ocean.