The PU Island swim is my favorite distance swim in Phuket; I have several locations throughout the Island but this distance swim I like best. I like to swim PU Island about 2 times per week, most of the time I do it early in the morning, usually before 1000 AM and during high tide.
The swim itself is very easy but I always do it with surface swim fins, neoprene top and swim goggles. I start this swim on the northern end of Kata beach and swim around the Island in a counterclockwise direction staying up 10 meters off the island as I make my way around it.
The swim takes me about 45-50 minutes using my surface fins. After spending years as a US Navy SEAL I have experienced all sort of beach and water conditions all over the world and have used some type of fins in all my water borne operations, so my recommendation is if you are going to do any distance swims in Phuket get yourself some fins, they can be a life saver in current conditions.
Check on my PU Island video brief for more information.