Specmar inc (previously specialty marine contractors) is an aluminum boat design, lofting, and kt company. we have a large product line including aluminum drift boats. A rigid hull inflatable boat (rhib) turbo-charged for fun! on our zodiac boat, whale watching is turbo-charged for fun. fast cat’s 240-hp inboard diesel engine is. Avon searider 5.4 metre rib avon have manufactured searider rib’s (rigid hull inflatable boats) in 4m, 4.7m, 5.4m, 6m, 6.4m, 7.4m & 8.4m lengths for many years..