Abstract: A high strength, low friction, corrosion free block for marine environments includes a fixed or swivel head, shackle and a ground and polished axle all composed of 17-4 ph stainless steel sandwiched between titanium/titanium alloy side cheeks. One or more aluminum sheaves each having a filament wound epoxy glass radial bushing with a Teflon liner are journaled around the axle. Oven cured Teflon filled thrust washers bonded to the sides of the sheave(s) turn against polished inner surfaces of the side cheeks. The blocks may include titanium/titanium alloy straps exterior the side cheeks supporting the axle to provide increased functional load bearing capacities ranging up to and exceeding 50,000 lbs.