The two must visit reefs
Great for vacations
Raja Ampat Reef, Indonesia
This wonderful tropical vacation destination is a great getaway, which includes snorkeling, enjoying the beautiful beach, and enjoying the hotel a accommodations. There are hotels that are located above the water so that you can step out and walk into the water. You will be needing your passport.
There is a low chance of catching malaria, and there are a few land animals that are dangerous, but are quite rare. Aquatic animals are pretty dangerous, but having a guide or a professional will minimize the chance of being attacked in the water.
Great Barrier Reef
Found in eastern Australia, the Great Barrier Reef is a great vacation location. It has one of the most diverse aquatic wildlife, which makes it a great place to go and snorkel/dive to see the beautiful vibrant colors that are found under the water. You can sun bath, swim, and do a lot of fun beach activities when visiting the Great Barrier Reef.
Precautions and Necessities
You will obviously need a passport. Since it is in Australia, there is a lot wildlife that could cause you harm, but it is not very common to encounter them, and if you do, then being cautious will help a lot. And again with aquatic wildlife, a guide or a professional should help with any danger encountered in the water.