Whytecliff and Lighthouse Parks are some favourite spots of mine. I can't remember offhand how you get to the water though, at Lighthouse, you kinda need to scramble down the rocks, do you not? But the whole park makes for a really pleasant walk and is not long of a hike. Your kids will love it (look for banana slugs along the way to the lighthouse
)
Whytecliff is a very popular spot for divers, so is fun sitting at that little rocky beach watching the divers coming in or going out. I don't remember seeing too many tidepools but there must be good ones there at low tide.
http://tides.gc.ca/eng/station?sid=7735