Some main types are the raked, flat, canoe, and reverse.
Raked
The raked stern is typified by the elongated overhangs of the CCA rules. The Cruising Club of America (CCA) put down rules about the water line length of racing vessels. To increase speed, racers would have long overhangs which when heeled increased LWL and speed. A raked stern combines usually with a long overhang bow. Some examples are the Bermuda 40 and Countess 44.
Flat
The flat transom can be plain or lovingly shaped like a wineglass or heart. The stern can be slightly raked but more often slightly reversed. From behind, the transom generally looks like a semi circle. The style traverses all eras. Examples include Herreshof’s Bounty and the Hylas 44.
Canoe
Canoe or double enders have a spherical stern. The boat ends in an aerodynamic way. They are standard for cruisers boats for traditional reasons and some say stability issues. The spherical stern smooth edyies away the flow of water. Examples include Bob Perry designs like the V-40 and Harris designs like the Vancouver 42.
Reverse
A reverse transom angles backwards from the waterline to the deck. A great example is the sugar scoop variety. A sugar scoop stern is a reverse transom which flexes inwardly, usually with swim steps. The easiest explanation is the picture to the right. You see the Hylas 49 which has such a stern. It gets its name from of course the actual sugar scoop, pictured later in this post. The boats stern is then not the end of the cockpit but actually a molded part of the hull. The cockpit end is set invisibly inside the hull going straight down from the sugar scoop’s upper lip. A sugar scoop stern is the most popular type nowadays.
Sugar scoop sterns provide easy access to the water. The crew can easily slip off and on sternwise to take a swim, launch the dinghy, or just drag their feet along lazily. Traditional sterns, especially a boat with high freeboard, are harder to climb. With a sugar scoop, the stern opens straight from the cockpit to the ocean.
Reverse transom yachts like sugar scoops effectively compare best to slightly smaller traditional models. A 45′ yacht with a sugar scoop compares more with a 40′ traditional transom. The reverse transom effectively adds an extra platform. The deck and storage space is about the same in 45′ reverse transom and 40′ traditional. The backwards slanted and stepped stern is only slightly volumnous. You can fit a little more junk into the aft of the boat or have a slightly larger aft cabin. The stern’s upper lip is more accurately the LOA than the lower lip. Therefore, the stern’s plus is the platform.
Conclusion
Stern styles include the raked, flat, canoe, and reverse. The choice is all about what appeals to you.