There is a very nice beach area with lounges, chairs, and small tables with umbrellas. The beach area also has a great view of some of the water areas, including the dolphin lagoon. Your husband could be your official photographer and could probably get some great shots of you and the kids in the water. He could even get some good shots of all of you with a video camera. He could do it from the beach, but would need a good zoom on the camera to get close-up shots. The trainers/guards at DC don't mind anyone taking pictures, but they will not let anyone climb around on the rocks for safety reasons.
There is a nice aviary that all of you cold enjoy. The birds are very friendly and will fly down and land on you, especially if you are holding out a cup of food for them. There are also a few little critters running around. I remember seeing some sort of tiny deer.
You could also have lunch together. The buffet lunch is very good and the portions are huge!
Even if your husband doesn't want to do any water activities, (sounds like my husband!), I think he would enjoy a day at DC just relaxing and watching the rest of you swim with dolphins and doing other water activities.