As an excursion Xel-Ha is great! Snorkling in the warm water lagoon and tubing down the river were great fun for all. A few downsides and things to note though; first, you are going to be walking and swimming all day, wear watershoes and consider the appropriateness and comfort level of your swimsuit (think your resort pool x 1,000). Go minimal as you will put most of your stuff in a locker. The yellow locker area is conveniently located but less used as everyone uses the red locker area next to the restaurant and scuba area. Biodegradeable sunscreen is not generally waterproof, wear a uv shirt or suit for better protection. A waterproof camera is a wise investment. Also, keep your scuba gear for the tube ride in case you abandon your raft in favour of swimming.
Price wise this was a bit expensive but it included lots of activities and transportation. The day is short though so plan in advance. It's 10 am before you get in the water and 5:00 when you get out and don't forget to break for lunch (buffet was included as well as drinks). Don't plan on a shower before leaving or you will lose time as EVERYONE leaves at the same time. Finding your picture (they take them everywhere) is a nightmare and visit the gift shop early or miss it entirely Plan to spend extra money for high impact activities, snuba, dolphins swim, bike zip, manta rays etc.
I wouldn't recommend this for weak swimmers and young kids although life vests are available (not worth the $$ for 10 minutes of scuba for a 6 year old). The kids play area is nothing special versus your standard playground, just a bit bigger. When going with kids, 2 adults are a must to divide an conquer.
Overall though a ton of fun for the prepared!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.