Swimming pool

The Sims
Swimming pools can be made in Build Mode. You can buy a diving board, and, if Vacation is installed, a pool slide. Swimming builds Body skill, and Sims think it's fun. Sims can drown if they use up their energy, so make sure you have a pool ladder in the pool.

The Sims 2
In Build Mode, a pool can be built on lots. A pool is useful for keeping your Sim fit and increases your Sim's Body skill. If you buy a diving board, your Sim can Dive. They will get better and better at diving. A Sim can drown if there is no means of getting out of the pool, so be careful.

With FreeTime, swimming increases Enthusiasm in Fitness.

Prior to Nightlife, building a pool in The Sims 2 was extremely cumbersome. Extensions to the pool needed to be a minimum of 2 squares and all pools must've been rectangular or square. Nightlife introduced the diagonal pool tool and fixed the problem regarding pool construction.