Yes, you can…if you know what beaches and be able to read the table of tides.
Before you go swimming and sunbathing in the Balinese waters, I highly recommend learning to use this table and check it in advance (you can easily find it on the Internet).
As an example:

In fact, everything is simple. The first line is timing, a lot of incomprehensible numbers is the water level in meters. If the level is from 1.5 and above - you can swim but be careful because almost all the beaches in Bali have quite strong ebb.

For surfers, Bali is a paradise, but the height of the waves does not depend on the level of water in the ocean. In case you are able to surf without instructor, then welcome to very useful website: magicseaweed.com.
Using this website you can determine where is the best to catch your waves in Bali. For example, If you are a professional surfer, you just should check for the waves 5-6 ft 🌊
More suitable beaches for swimming:
1. Melasti
2. Geger
3. Gili Air
4. Gili Meno (one of the best beaches in the world!)
5. Gili Trawangan (many people come here to snorkel)
6. Sanur
7. White Beach (White Sandy Beach)
8. Pandawa
9. Karma Kandara
10. Gunung Payung (Gunung Payung)
Have even visited these beaches?☝🏽 If so, which one is your favorite?