We found a nice corner of Arugam Bay beach called Baby Point which is perfect for learning to swim!
It is sheltered from the waves by the main point break, so there are just little one-footers that break right on the beach. The water depth increases very gradually, so it’s easy to sit with the kids and lift them over any bigger waves.
It’s also a very entertaining corner of the beach; there are fishing boats coming in loaded to the gunwales with sardines and fish blood, local people swimming and taking pictures of the foreign kids, surfers headed out to the main point break, and ox-drawn carts hauling supplies and surfboards out to the hotels further down the beach.
The only downside of little Baby Point is that it is at the other end of the beach, but it’s only a 100 rupee tuk-tuk ride. Of course, since we’re super thrifty (or cheap if you prefer) we often choose the 20 minute walk in 40 degree heat. But we save one dollar (89 cents actually) so it’s probably worth it.