Our West Highland Terriers love the water. They like to swim in pools, ponds, lakes, even the ocean. We've actually purchased a few pools for them over the years. Sometimes their claws put leaks in the pools. We've had the most luck with hard plastic kiddie pools, like the one pictured above.
If you already have a pool and your West Highland Terrier likes to swim in it, there are products such as pool steps, life jackets for Westies and pool toys for Westies. Never let your Westie swim unattended. Protect your Westie.