Our exclusive, custom-made Carbon-Fiber masts are superb. They are designed to have just the right bending characteristics for the class specified. The 70" 36/1M mast is about 7/16" at the base, 11/32" at the top, and weighs about 2 oz. The 90" Marblehead mast is about 1/2" at the base, 3/8" at the top, and weighs about 3.4 oz. A 75" version is also available. The 90" 10-Rater Mast, also used on the Marblehead Swing rig, is about 9/16" at the base, 3/8" at the top, and weighs about 3.7 oz. This mast can also be used for a Santa-Barbara, with the top part being used for the jib boom. The 100" AC mast, also for the "A" Class, is 5/8" at the base, about 7/16" at the top, and weighs about 4.5 oz. All masts are now made from 44M modulus Carbon- Fiber, which is about 30% lighter than our earlier masts while maintaining the same stiffness. Boom material is straight, 1/32" wall, 33M modulus Carbon- Fiber tubing, and is available in many sizes from 5/16 to 13/16" O.D. It is also useful for making Mast trunks for keel-stepped masts. Quantity discounts are available on masts and booms. Custom masts can be produced up to 120" in length. Please call for quote or further information. We now have clear anodized, 6005 aluminum, masts and booms available for the IOM class. The 7/16" OD mast tubing is supplied as a single 72" length, enough for a #1 rig without joining. The boom tubing is 3/8" OD and is available in 36" lengths. If you have any questions, please email me at: rcsail@ca.inter.net