You can get great shots from the observation deck. We also bought the DVD and all the pro photos. They were all great in their own way. For instance, we heard the trainer tell one youngster, "Come get your sea lion hug again, we are going to retake it since your photo was blinking." Not sure how the photographer silently indicated this to her, but he got an extra hug and I was impressed that they were looking to ensure that all the photos turned out great and not just sell us junk. They are great too, some of the best we have seen. You don't have to buy them, but as it was a family affair, we were happy too.
I'll give you examples of each so you can decide (although if its in the budget, it makes great family experience to do together!) Us 3 daughters did the encounter and Mom & Dad came back for the educational part and observation. They could take as many photos from there as they wanted, and he took probably 100 and they are all good! (Of course, he had a good lens too.)
as for the water, we went in April. Older sis brought her wetsuit: VERY SMART! It was chilly but worth it. Also they do offer you wetsuits there, but we were too 'just fine' for that! It will be warmer at least a little than when we went.
These were from their own professional photographers:
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These were taken from the observation deck, and are nice because they show the 'candid' moments!
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https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-ash3/601828_110171579185101_1915609687_n.jpg
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We enjoyed our entire day. We liked the island food like the conch fritters and fish. The snorkeling is hard to get to because you have to climb over rocks, but the reef side beach is much less deserted and very very relaxing so I recommend that beach for relaxing and the lagoon for swimming as a family.
We had a great, great family memory and think you will too! We will be back to do the dolphins next time I think. The Sea Lions were so unusual and it was great. The dolphin you can see in a lot of places, although this looked like a really good one! You can observe the animals as long as you want. It was so nice not to be rushed all the time.
We took the very last ferry of the day and still got back to port with enough time to go shopping and still have about 20-30 min before all aboard to check back in.
A very magical day indeed for us! Hopefully for you too!