When is it okay to bring LO to swim? Need thermal swimwear? Waterproof diapers? Where to get it? Thanks

I think when their neck muscles is strong can bring them to swim. I let my gal dip when she was about 4 months. I bought an inflatable pool from Swimava so that my gal can dip at home with warm water. You can also bring her to Baby Spa. I also bought thermal wear for her from Konfidence brand. There was a spree on one of the motherhood forums so the price is much Cheaper. I feel thermal wear is better because babies may catch cold easily if dip in normal pool water. As for reusable diapers for swimming I let her wear the brand Charlie Banana which can be bought at Mothercare. And I always limit her time in water to 20mins Max.