POLYFORM

A-1 SERIES BALL BUOY

BOAT SIZE: 20 to 30 ft.

SIZES: Eight sizes from 8 in. (for boats to 20 ft.) to 39 in. (for boats

70 ft. and up); our test fender was 11-by-1 in.

COLORS: 18 (including eight shades of blue)

PRICE: From $25.58; westmarine.com; polyformus.com

Here is the only fender properly called a buoy. It mimics the original design of Japanese glass-net floats and is used by fishermen to replace the glass floats. (They haven’t been used in decades, though beachcombers still find them today.) Polyform ball fenders come in 18 different colors to match any boat’s finish, and eight different sizes, from 8 inches in diameter for boats up to 20 feet, to 39 inches in diameter for boats 70 feet and up. All sizes have a valve under a screw cap that allows air-pressure adjustment for expansion or contraction, or to deflate for easier stowage. Ball buoys are best on taller-freeboard boats moored against flat, vertical surfaces, such as the sides of lock canals or other boats. They resist riding up the sides under friction with another surface thanks to their shape.

BEST USES: These are lifesavers when the gunwale extends out beyond the boat’s side, and are particularly useful toward the pointy end of the boat where the bow flares over the sides. Secondarily, they’re used as a Bimini windlass. It’s an old trick that uses a steel hoop around the anchor rode. First, be sure the anchor is free of the bottom, let it lie there, then drive away at a good clip to pull the rode through the ball’s hoop. Once the anchor shank runs through the hoop, stop and coil up the line. It’s a real back saver for bottom fishermen.