In general, yes, but there are several risks associated with swimming under waterfalls in the state of Hawaiʻi that you should be aware of. The most important is the water-born disease leptospirosis: don’t go swimming if you have any abrasions, scrapes, blisters or other skin lesions. Flash floods are also a risk, so stay out of the water if it’s raining (where you are or upstream). Read more about waterfall safety.