Pat, The engines are a pair of Yanmar diesels 4LHA-DTP. The 19 knots is achieved at 2560rpm I believe. I will check this and confirm. Regards, Malcolm Tennant. MALCOLM TENNANT MULTIHULL DESIGN LTD PO Box 60513, Titirangi. Waitakere 0642 NEW ZEALAND Ph: +64 9 817 1988 e-mail: malcolm@tennantdesign.co.nz www.tennantdesign.co.nz www.catdesigners.com