Mushroom

Prove me wrong but I think charging for towels is a huge bluff, have never heard of anyone getting a charge. And if you were to get a charge there is nothing to stop you from taking one off of a chair, creating a bigger problem, especially if that person does the same thing.
Once when I returned two towels and they only scaned my card once and I had to bug them to do the second scan, got the feeling from them that it did not matter.

Depending on the amount of kids in each group, they may combine. On our recent Freedom sailing, my daughter (8) was in Explorers, but they occasionally were grouped with the older group (9-11?)...

My wife panicked one day when we came back from an excursion, left the pool towels in our room and went to dinner. Well, the stateroom attendant made up our room and the towels were gone when we got back... lol  Never did get a charge, but I assumed he would check them in for us. Or the $25 threat is to keep you honest.... 

On Grandeur - at least as of September, they scan your card when you get them and when you return them .... They're really great towels .... I know my wife was real tempted to purchase a couple of them off of Amazon (she still might, who knows)

Royal sells them online for 15 dollars last time I checked, they looked a bit nicer too. It's where they sell the Royal bedding.

If your son is younger and wouldn't be OK to go by himself, then one ticket is fine. If he's older and you're OK with letting him go on his own (needs to be able to use the hand brake at the end), then maybe get two tickets so he has the option.

Thank yo DocLC!

They will give you a form to fill out indicating what your departure arrangements are and theoretically assign a time based on your departure plans.  On one of the last days of the cruise, they will give you numbered luggage tags and a sheet indicating the approximate departure time for each number.  If this is too late for you, you can always request a lower number at Guest Services.  If it's too early, just use the tags and depart the ship at your leisure.
 
On the last morning, they will start calling numbers and you're asked not to line up to leave the ship until your number is called.

Just got off Harmony 2 weeks ago. Let me clarify. Your sea pass card is no longer given to you in the terminal. You will find your cards in an envelope on your bed. The doors are propped open and you are greeted by your steward to accept the cards (after 1:00pm). You can still make purchases and these purchases are made with the bar code on your set sail paperwork that you print out prior to cruising.

On cruise days, the pool towels are available on the pool decks. On port days they are available on the exit deck. I have been on some ships where they scan your sea pass cards when you get them an scan when you return them. I have also been on some RC ships where the towels are available with no scanning of your sea pass card. The pool towels used to be logoed, but not so much anymore. They are big, in pretty good shape and blue in color. You can get as many as you want also. Pool attendants will remove them at the end of the day, like around 5:00 pm-ish.