My family of four (2 adults and 2 children aged 8 and 6) went to the Similan Islands on a speed boat. We stayed in Khao Lak so it wasn’t too far getting to the port. Snorkelling gear, food and drink were all included. We were expecting a buffet lunch but instead had a lunchbox given on one of the islands (I suspect because the tours don’t have access to electricity). The food was pretty ordinary consisting of tasteless and cold spaghetti, rice, pineapple salad and 2 of the tiniest pieces of chicken I have ever seen. The beaches themselves are absolutely stunning; white sand and turquoise blue waters surrounding rock formations in the water. I’d recommend doing the small walk up Sail Rock. It takes about 10 minutes up and down and my children had no problem doing it. It’s a bit rocky but there are plenty of places to hold onto so you can take it slow. You will be rewarded by breathtaking views and be able to take some fantastic pics.