There were a lot of kids on the cruise including hundreds of 15 year old girls from Bolivia celebrating this special birthday in their culture. Additionally there were MANY families on board, but at no time did I feel that the kids detracted from my cruise experience. They were all very well behaved and that probably has much to do with the amount and variety of activities available to them. The adults-only solarium is a God-send...quiet and relaxing as opposed to the general pool area which could be noisy and crowded.
As for motion sickness, I never had an issue on board except for a small amount of discomfort in the theatre (up front and down low). The ship is huge and while we were moving at a clip at times, the sailing was very smooth and the motion barely noticeable.
Staff on board was helpful and enjoyable. It was truly like staying in a very upscale hotel. The public spaces are beautiful and the artwork on board is unbelievable. For the most part the ship was immaculate. I only noticed issues with cleanliness a few times in the highly used pool area and sports/recreation area.
Cabins are highly functional and I never felt crowded. There was a place for everything. The balcony was quite enjoyable and provided a very private outdoor space. I highly recommend a balcony cabin. It was well worth the extra money and I would never cruise without one.
Ports of call included Belize, Costa Maya, Cozumel and Georgetown, Grand Caymans. In Belize I highly recommend making plans for a shore excursion. There is really nothing much at the tender dock other than a few shops. We booked cave tubing through Coral Breeze (half the price of the ship's excursion) and were subbed out to Wet and Wild. Owner Marvin took our small group of ten on a wonderful outing and I had the best meal of the entire cruise at the conclusion of our tubing experience. Ship tours are too large and included about 60 people. Don't be afraid to book this excursion on your own.
Costa Maya was beautiful. We didn't plan an excursion. This is a pier port and we were able to walk off the ship to a "tourist village" with a few restaurants and many shops, a pool and a beach area. Save your shopping for Cozumel.
Cozumel, we spent the morning enjoying a nearly empty ship. Have lunch at Johnny Rockets on these port days. You have the place to yourself and their burgers are excellent; their drinks and shakes worth the "nominal fee". In port you'll need to take a cab to do some great shopping in town. Silver is the thing to buy. Check out "Los Cincos Sols" a very friendly store with everything you could want and more. Have a chilado (mexican beer and lime juice) at Los Palmas...so much more affordable than the ship. Our bar tab from the week was high due to martinis that are $9.20 each. A $12 bottle of wine here at home, is triple that in the dining room. Royal Caribbean definitely makes their profit on the alcohol and soft drinks, not to mention the nominal fees associated with some activities and those souvenir photos.
In Georgetown, we joined our friends for a ship's excursion on the semi-submersible Nautilus. We headed out to Cheeseburger Reef for a fabulous snorkel. This excursion was super enjoyable as there were only 8 people on board the boat, when in fact there are normally 90. Only 4 of us snorkeled, vice the 60 that they normally have in the water. This gave us MUCH more time in the water than we would have had if the excursion was full. Not sure why it wasn't but we were very fortunate.
Food was fine, nothing fabulous but good choices, served at the proper temperature. Avoid the cafeteria eating in the Island Grill/Windjammer Cafe, especially if you're not travelling with children. Eat in the dining room whenever possible. The service makes it so much more enjoyable as opposed to picking up your own tray and filing through the line, then searching for a table.
Embarking the Explorer was a breeze. Advice when disembarking...head to the front of the ship. Everyone was attempting to disembark from the aft. We waited in line for 25 minutes before we overheard someone say that there was no line at the other disembarking station. We walked right off and then waited maybe 30 minutes to get through customs.
So...I'm sold on cruising on this class of ship. The week was absolutely fantastic and I'd go again in a heartbeat. Do not hesitate to book on the Explorer of Seas and definitely find an opportunity to snorkel at one of the ports. Cave Tubing in Belize is awesome.