This is the easiest and best thrill you will get in Oahu - just rock up to the desk on the sand in front of the Royal Hawaiian, hand over $25, wait for the boat to fill, and off you go.
There are no set times, the boats go whenever they have the minimum 4 passengers to make it work, so, booking ahead may save you a wait.
But they are good at putting people together and calling when the crew is ready to go so you can also just turn up, as we did.
They take casha nd credit cards, and can look after your gear at the desk.
The paddling out requires some exercise, but it's not strenuous, and then catching the waves is an absolute blast.
As a bonus you get awesome views of Waikiki and Diamond Head as you dodge the swimmers and surfers on the way back in.
An absolutely essential Waikkiki expereience.