The cornrolls are $2 each (which is the braid that is suppose to do half the head)
You make reservations at one of the shops ( I believe it is the shop that has more adult stuff in it) I cannot remember the name of the store though. They take the ressies then.
I have two daughters and I had one of my daughters done on Sunday and she was the first of the day. They do not take the braid back very far (like 1 1/2 inch.) It was not half way back. My other daughter seen it and did not care for it as we weren't that pleased either. They also were a tad bigger which means you will not be able to keep them in as long once you get back home.
When we got to St Maarten we had my other daughters hair done there and they also re-did my first daughters the one that had hers done on the ship. They charged $1.00 per braid. The nice thing about it there was one of my daughters hair is kind of making a "V" and the other one angles to the left a bit. They made it different on both girls which looks really nice and they did not charge me extra to take the ones out and re-do it. They are also much thinner braids that will stay in longer.
For example my friends daughter had hers done on the ship after mine and she told the lady (Paula) that she wanted it to go farther back so it is half the head indeed and it was done but under protest and many complaints from Paula (the one that did the braiding) She also took her daughters out this weekend because they were starting to come out already. We sailed on 10/19. Both my daughters looks like they were just done. We got so many compliments from people on the ship asking who did their hair because it was a bit different than the traditional straight back braid.
I would do it on an island again instead of the ships it is half the price, stays in longer and really (IMHO) looks much nicer. I would also recommend you bring your own comb with you though just for sanitary reasons. (I believe this for both though) you never know.....
Sorry to be so winded just wanted you to know all the facts ......Good luck and have a great trip!