I know of mothers who would send their child into the pool that way and then still scream bloody murder themselves if his hand needed to touch her chest

Ew, you may be right - I read about people like this from third parties every so often. Never seem to encounter one first-hand, online or off, but via third parties.

None of the swimming teachers seem to get into the pool with the children, it's all from the edge coaching. But he might need to touch them sometime anyway.

Rob found a blue spotty tankini thing in a sports shop. Sports shops sell swimwear all year round, apparently.