Price is a main factor when choosing a charter boat. Some boats are way more expensive than others, but be aware because often an expensive boat does not necessarily means a better boat. In fact some “not-so-good” boats have very good marketing and consequently are almost fully booked, so they push their prices up.
Boat characteristics are another main issue to take into account: usually a bigger boat is safer and more comfortable. A boat with two engines is also safer than a boat with one single engine, and it’s faster.
The surf-guide is also very important: a bad guide can ruin your holiday, or just make it pretty much average, as much as a good surf-guide can find you the best waves of your life! …and away from the crowds.
Before committing to a boat ask someone who as been on a boat trip before about boat conditions, surf-guides, etc.