A really great experience and well worth the time and money. We swam in caves, saw bats and starfish and beautiful coral. Our guide Yannis was terrific, with interesting stories, facts and even singing! I an 61 with a little kayak experience on rivers, I found the kayaking part relatively easy, I reckon anyone with a reasonable degree of fitness would be fine and Yannis will make sure you are fine. Don't forget suncream, hat, swim gear and drinking water!