From the original Kelly Peterson 44 and then the Kelly Peterson 46 there have been a number of copies or others based on the originals. Some official and some not. Most notable of the unofficial copies were the boats built by Formosa.
Sailboats based on or copies are:
- Delta 46: Based on the PETERSON 44 and LIBERTY 458 but with different interior and sold in Europe.(Delta Marine was a German company.) Cutter or ketch.
- Formosa 46: Yet another altered version of the KELLY-PETERSON 44 (PETERSON 44 CUTTER), first offered in 1976. (Often, as in this case, with out the payment of design royalties.)
- Liberty 458: Said to be An extended version of the PETERSON 44 hull design with a different deck and coach roof. Another version is the DELTA 46 from the same yard but with a different interior and originally intended for the European charter trade.
- Passport 45 (Hoyt): From Peterson 44 mold which was also used to build the Liberty 458.
- Spindrift/Hillier 46: The SPINDRIFT 46 was built by Formosa Yachts using the same molds that built the FORMOSA 46. (1980-1984). R. Hillier, of Brisbane Australia, oversaw the building of this yacht which was to be sold in the US for Bristol yachts of Newport Beach CA. For the Australian market, they were called the HILLIER/PETERSON 46. Hillier ran afoul of designer Doug Peterson who filed a law suit. Hillier died and the suit was shelved.
I would not be surprised if there are more, this is just what I have found so far.