Compare the speedboat and big-boat experience side by side.
Speed buys you island time. Cross the open water quickly and the hours you save get spent ashore instead of staring at the horizon. Three kinds of speedboat go to Ang Thong, and they are not interchangeable.
The workhorse. One day, and it usually holds the Emerald Lagoon, a kayak session, a swim or snorkel and Koh Wua Talap. If you have no strong preference, start here.
Same sea, fewer people. You notice it at lunch and at the kayaks, where nobody is waiting in line. Couples and families who hate a packed deck usually think the extra money was well spent.
Two hulls instead of one. That means a wider deck to move around on and a ride that feels different from a narrow speedboat. A middle ground between quick and roomy.
When the wind is up, yes. The hull slams and you feel it. Sitting toward the back helps, and the crew will tell you where. Talk to a doctor first if you get seasick badly or have a heart or back condition.
It depends on which pier you leave from and what the sea is doing. What is reliable: a speedboat is the fastest group option out of Koh Samui.
On the standard, VIP and catamaran tours we compare here, yes. Listings change, though, so give the tour page one last look before you pay.