I'm really not sure how that would work. I know you have to be at least 3 to do the excursion. If both mom and dad wanted to do it, I don't see why they couldn't let you take turns holding the 2 year old. There is a long wooden bench near the lockers that overlooks the encounter area you could sit on and watch (and take pictures!) and then switch. It's a good 5 to 10 minute walk from the encounter area to the beach area. There are also a couple shops that are very close by that sell pictures and some t-shirts, etc. you could walk around in with your 2 year old. I'm sure they've encountered this situation many times before and they could answer your questions for certain if you call to book it. My 2 boys absolutely loved this excursion, and we will definitely do it again when we cruise again. My husband and I did the dolphin excursion in Cozumel last November, and the Blue Lagoon encounter was so much better. Have Fun!