Generally, scuba snorkels come in three different types - classic (or open top), semi-dry and dry. The choice will depend on your most common usage scenarios.
A classic snorkel is open and has no valve at the top. It allows the water to enter the tube freely when submerged. There usually is no purge valve either, so you will have to clear such snorkel by blowing the water out through the top. The benefit of open-top snorkels is that they are very lightweight and create less drag. Many are foldable, which is a desirable feature for scuba divers. They are also the cheapest option.
A semi-dry snorkel comes with a splash guard on top. This helps to keep some water out while at the surface but won’t stay dry once you go underwater.
A dry snorkel is designed to seal all the water out with the help of the special valve on the top of the tube. These also include a purge valve, so that you can easily clear the water in case some small amount does enter the snorkel. Dry snorkels are usually the most expensive and the heaviest out of these three types.
DIPNDIVE carries a full line of Scuba Diving Snorkels in different styles and price ranges. The diversity of snorkel sizes and colors we offer will make it easy to match your mask and the rest of the scuba equipment.