We go to Marineland every year. They do a lot of group ticket sales. If you have kids who play a sport (our soccer club has a deal) or you work for a major company/union, chances are you get a deal but have to buy the tix through them. Marineland also usually has a deal where, for five bucks, you can upgrade to an annual pass for the year. Marineland is not comparable to SeaWorld. It is cheaper than SW but not as clean, not much in the way of dolphins and pretty basic shows. They do have a lot of Belugas and you can pay extra and feed them. They also have a Killer Whale splash show where you get quite close to them and, well, they jump around in the pool and you get wet. My kids love feeding the bears. Forgo the deer encounter, I'm not even sure it's humane how they have them. The rides are okay but not spectacular but are included in admission. I don't enjoy the rides there but my kids do.
You can bring a cooler into Marineland and I highly recommend it. Marineland food is not any chain company. What it is is greasy and overpriced, and for some reason there's always tons of bees in the picnic area behind the main restaurant pavillion.
It's not a bad day out. For my buck, I much prefer the Toronto Zoo, but some people love Marineland . The rides at Marineland are not in the same league as the rides at Canada's Wonderland.