Does anyone know, after gromet insertion can you go swimming or how long do you have to wait?

A few weeks: Hi It takes a few weeks. Mostly we're waiting for the ear drum to heal around the grommet itself. After that swimming is generally ok. If you can get the soft earplugs that just sit on top and don't insert into the ear canal, that's better. I'd also stick with surface swimming in a swimming pool or ocean only. Avoid diving and lakes/ponds which can have higher amounts of bacteria.