Futures Al Merrick Keel Twin Fin (Large) The Al Merrick Keel (AMK) by Channel Islands is a modern take on a classic design. The AMK features a modern rake and graduated tip flex that’s finely tuned for fast, high performance surfing. This keel-fin design is built to rip, but also ideal for those that just want to groove. Template Category | Keel (speed control, drive, trim) Construction | Fiberglass Size | Large Twin Side Fin Area 25.54 Height 5.15 Base 6.46 Foil FLAT