Designer Rob Humphreys | Sailing Blog - Technical Hints and Tips - Sailing Television

Designer Rob Humphreys

A highlight of the Southampton show for me was meeting Yacht Designer Rob Humphreys. He has designed a great variety of boats over more than 35 years from racing sailboats to super-yachts. He has worked with Northshore for years improving upon the Southerly Swing Keel and he also designed the Southerly 42. Now he has designed the hull for the new 49. It was largely because I think his hulls are so good that I wanted to sign up for the new 49 even before I had a chance to sail the first one last month!

We had a chance to chat and Rob had a number of comments about the 49, and Southerly’s in general. Rob’s first comment was one I had realized when we sailed our 42 offshore. “Southerly’s are not constrained by the normal design restriction of needing to have a shallow keel. Most keels are a compromise since cruising boats can’t draw too much, or else they would be limited in their harbours and anchorages”. Our 42 draws 9 feet!!

This makes a very good upwind boat and a boat that is very stable at sea in big waves. Basically since the keel will be raised in shallow waters, Rob is free to make a deeper keel than any normal cruising boat or cruiser/racer. We find that swinging the keel down all the way makes the boat roll far less than other boats we have sailed on.

Southerly’s also have a very good motion at sea thanks to the high total ballast. Since the keel will be swung up and down, the boat needs to have sufficient ballast even when the keel is up for safe passaging. This is accomplished by the heavy “grounding plate”, in combination with the keel weight. The combination makes for a smoother ride in rough seas, but the long waterline length makes her fast as well. Here’s the keel and grounding plate for the new 49. HUGE!!

We also talked about the rudders. Having twin rudders means one will always be deeply buried, and since they are angled outward, the working rudder has a good angle as well. A second benefit is that when sailing downwind you have both rudders buried and extra stability.

Finally we discussed swinging the keel up. Its another advantage to the Southerly in that you can raise the keel to any desired position. So sailing downwind in calm seas you can raise it entirely to reduce drag. Or sailing in bigger seas where you still want keel stability to reduce roll you can raise the keel partially. Not only is drag reduced, but you also move the centre of lateral resistance aft making the boat easy to balance downwind. We did this much of the time crossing the Atlantic with the 42.

It was a privilege to meet Rob and now I am really looking forward to sailing the 49 in some more boisterous conditions to see what she can really do!!
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