About: BJ Porter

Website
http://sailevenstar.com
Profile
Owner of Hallberg Rassy 53; world explorer.

Posts by BJ Porter:

Catamaran Construction – Hulls, Laminates, and Composites

It’s a given that catamarans are more sensitive to weight and loading than monohulls. Catamaran builders strive to build the lightest boats they can without sacrificing strength and stiffness, and have adapted new building techniques and materials to meet this target. Cutting weight allows more passengers and gear without sacrificing performance. And the marketing materials reflect it–they load every review and website with polysyllabic technical jargon describing the design and production choices each builder made to deliver the best boat they can. But when you’re reading a brochure and you come across phrases like “hand laid bidirectional GRP” or “vacuumed bagged e-glass with vinylester resin over a Divinycell core” do you know what that really means? All modern production catamarans are made with “FRP” construction (for Fiber Reinforced Polymer). Composites aren’t new–it’s just using materials together to strengthen the whole assembly. Straw was added to bricks centuries ago, and steel […]

Knysna 440 Review: Upgraded St Francis 44

In 2002 Knysna Yacht Company (pronounced “Knees-nuh”) set out to become a boutique builder for high quality, semi-custom catamarans. Building on the legacy of the South African catamaran industry, the company purchased the tooling for the Angelo Lavranos designed St. Francis 44 hulls. Then Knysna changed the cabin and interior layout and the weight balance to launch their own take on the cruising catamaran. The Knysna engineers found that the St. Francis 44, a successful cruising design, still had room for improvement in areas of interior volume, cabin height and weight distribution. The original design had center engine placement in the hulls, but the Knysna team moved the engines towards the stern and added a small stern scoop to to increase sea kindliness and motion. Moving the engines aft gave the new team more space to work with mid-ships in each hull and gave the boat more lift in waves, […]

Leopard 44 Catamaran Review

History / Background South African boat builders Robertson and Caine have built over 2,000 catamarans over the last three decades. The Leopard 44 results from another successful collaboration with American catamaran designers Morrelli & Melvin. The goal was a solid, affordable mid-sized catamaran capable of blue water sailing and good for the charter market. Multiple awards and the boat’s enduring popularity show how well they hit the target. The Leopard 44 starts with a hull construction of vacuum-bagged balsa cored e-glass with vinylester resin. This makes for a light, strong and blister resistant foundation to bond the fiberglass liner. The interior layout is open, to make a galley and living area combination which keeps the cooks in the mix with everyone. The common area living plan feels open, and social and light, like a casual dining roomand open kitchen plan in a house. They built two versions of the boat—a […]