NO, Do try and look for ships with lots of activities like skating and rock climbing. Arcadia is a lovely ship but not many people of your age use her, especially if the cruise is non-fly. Most non-fly cruises are used by more elderly passenger who far outway those people who do not like flying.
The Arcadia is an adult only ship, and would be unsuitable for young adults. Depending on what you are looking from the ship it may not be suitable. If were a nice relaxing time your looking for with not many activities then yes it would be suitable. However if your looking for activity centres on-board for example - climbing walls, ice skating, surfing then it's definitely not the ship for you.
Thankyou for your help.
Absolutely not. I think the best ships for this age group would be American ships eg Royal Caribbean, in the Caribbean, eepecially at easter when American students traditionally let their hair down. Also summer holidays. At other times the average age on all ships is too high for your older teenager to find congenial companions and activities.