In terms of getting the little ones contently tired, there really isn't anything better than a good swim in the pool (or ocean, if you are lucky enough to live in warmer climates). We went to a swimming class in Notting Hill this morning and the little ones have been napping now for over 2 hours and are still fast asleep !
We have been going to swimming classes since the little ones were just about 3 months old. They absolutely love it.
As we are now in the "advanced" class, we get to do quite a few underwater swims. The first time we had to go under, it was a bit scary but now we really enjoy it. It doesn't seem to bother them at all. Actually, I think generally the mums (and dads) seem more nervous than their babies. In fact, I was told that babies naturally hold their breath under water up until they are about 6 months old. That I find incredible.
Apart from just having fun in the water they also learn various helpful things like, how to find their way back to the handrail if they fall in, how to hold on and pull themselves up onto the rail etc.
You can find out more on www.waterbabies.co.uk