You need to look for a lightweight boat with a high stability factor and a large, trimmable rigg, if you are considering participating in regattas or other competitions. Also, decide whether you want to sail racing in a certain boat class or whether you want to sail according to a handicap rule. Have a look at World Sailing for the definition of handicap rules and ratings.
Racing places special demands on boats and equipment. In principle, you can of course sail competition in anything, but if you prioritize a specific type of race, then some boat classes are certainly more interesting than others.
Race boats are most often equipped with a deep keel, a narrow foreship and a large rig with loads of trim options. You will have noticed that on race boat of recent production years you’ll see a broad and flat aft. As it stands, race boats are often better suited for open sea sailing, as touring boats typically have a lower stability.
What type of waters should the boat be able to handle?
Where do you want to sail with the boat? Most boats can do far more than they are exposed to.
Most boats from 25 – 30 feet and up can sail on the high seas if the skipper and crew are competent and the boat is properly equipped and maintained. Some boats are best suited for protected waters, while others are designed from the start with high seas and severe weather in mind. There is no need to have a fully equipped around-the-world yacht if you sail in local waters and rarely or never go out in the big open seas. The reverse situation is probably less common, but of course, you should not buy a sensitive lightweight boat for flatwater if the plan is to sail the oceans. In other words, it’s a good idea to check the normal wind and wave situation in your local waters. Also, talk to experienced sailors and see what others are sailing!