of . The TS16 was built in large numbers in New Zealand and Australia, spurring the popularity of trailer sailers in these countries. Over 12,000 boats of this type have been built. The advent of mass production fibreglass boats in the mid 1960s saw an expansion of trailer sailer designs, such as the Aquarius 21 Boomerang 20, Cal 21, Careel 18, Neptune 16, and Pearson 22. The Catalina 22,launched in 1969, is particularly notable as it continues in production, with over 15,000 built. Trailer cabin sailboats appeared on the US market in 1970 and were sailed on small lakes and rivers. A large number were initially sold in North America in areas such as Arizona, New Mexico and the Great Lakes region. In the late 1980s and early 1990s trailer sailers evolved into sportsboats, of a similar size but more optimised for racing speed with reduced accommodation and lightweight hulls. There is an absence of an accepted definition of the term. Accommodation Cabins in trailer sailers are usually arranged with dual purpose settee-berths running along the side of the boat from a V-berth at the bow, to quarter berths underneath the cockpit. Usually, the centreboard or daggerboard trunk encroaches into the cabin in the middle of the boat, but can form the base for a folding table. Some types have a small four person table with club seating. Boats may or may not have a small galley with a stove, a food preparation area and a sink. In terms of headroom, the smallest types do not have sitting head room for taller sailors, while only the largest have standing headroom. Some boats address this problem using cabin pop-tops that can be raised when not underway to provide additional head room. The smallest trailer sailers in the range generally have two berths. As boats become larger four berths are commonly fitted, with a V-berth at the bow and quarter berths at the rear. Larger boats might have up to six berths. Many trailer sailers have a small galley with a stove, built in, although on smaller trailer sailers, this may be omitted. Usually, trailer sailers have a head, which is most commonly a portable toilet, mounted in the bow V-berth area of the cabin. Some larger boats however have an enclosed toilet. Towing Trailer sailers, by necessity, must be transported by trailer, which places a number of restrictions on their design.