Low Tide

Yacht Designer Tad Roberts' Web Log

general design

What is a “Bristol Channel Cutter”?

Marketing doublespeak…….We’ll build a fat little boat and call it a “Bristol Channel Cutter”, that’ll bring in the rubes……And it did and still does. The Hess designs are in reality pretty much the exact opposite of the original Bristol Channel Pilot Cutter’s, in that they are wide with lot’s of form stability and minimal outside[.....]


Stability information presented to the public is usually simplified to the point of being useless. When I see a published stability curve like that above, my reaction is “That’s nice and it looks good, but it tells me almost nothing.” It’s a nice graphic but key information is missing, mainly data on the conditions under[.....]

Sheerline Problems

Many think the sheer is the most important line on any boat. Get it right and all else is forgiven, get it wrong and nothing else matters. To some extent this is true, this one line in 3D space, must be attractive when viewed from any angle. If it’s filled with humps and hollows from[.....]

R2ak – The Race to Ketchikan

The first sail and oar race to Ketchikan will start on June 4th, 2015, from Port Townsend Washington. That makes the race course about 750 miles of wilderness and open North Pacific Ocean, mostly through BC waters. There are a few Canadian boats entered, and we think the Barefoot entry from Silva Bay will be[.....]

Cruising Speed Under Sail

I’m starting to think it’s all rubbish. Sailors love to compare boats, “that’s a fast boat”, “That boat is horribly slow”. One of things that constantly amazed me when officiating during the Shipyard Raids was how close the speed of the various sized and shaped boats was. This was longer term speed, not momentary peaks[.....]

Varua and Starling Burgess

From The Circumnavigators by Don Holm “Varua, which means “spirit” or “soul” in Tahitian, is considered by many aficionados to be the most beautiful and functionally perfect sailing yacht ever built.” Above are the hull lines of Varua, designed by Starling Burgess in 1940. In More Good Boats Taylor reports that Burgess and Robinson tested[.....]

An Interview With Me!

Bob Wise over at Boat Bits published an interview this morning……..Sort of a “where does it all come from and where’s it going?” At least he didn’t ask which boat is my favorite….the un-answerable question…….. Here it is – Chat with Tad Roberts And here are a couple of favorites…….the hard-working Sophie & Seka in[.....]


Lessons in Appropriate Architecture Appropriate architecture (design) applies to both buildings and boats, as well as all the other manufactured items we use every day. Appropriate materials, aesthetics, how something fits in terms of surrounding environment, use, and historic context are all central to appropriate design. My first lessons in architecture came from my Grandfather,[.....]

Sailing Yacht Proportions

The first fundamental of great design is basic proportions, if you get those wrong the rest is just window dressing. I was stunned to see a full page ad in the latest Classic Boat featuring really bad proportions. See the new 56′ from Spirit Yachts above. Everything is wrong, the sheer is too high, too[.....]

Design Ideas and their History

Design Ideas Where do ideas come from? It’s a long and tortuous path. Today I happened to note an arrangement concept for a new design by Gerry Dijkstra that seems to be directly descended from one I conceived 15 years ago. For me the roots of this idea lie in the 1961 E.G. Van De[.....]