KEEL, DRAUGHT AND DIS­PLACE­MENT

Yachting World - - Front Page -

In all my re­search on the sub­ject of ideal draught and keel type, there was a con­sen­sus that a fixed keel may be bet­ter suited for ocean pas­sages, whereas shal­low draught, whether with a shorter keel and bulb or a cen­tre­board ar­range­ment, was prefer­able when cruis­ing. My two last boats had a cen­tre­board and I can state un­equiv­o­cally that both from the safety and con­ve­nience point of view, a cen­tre­board works per­fectly, both when ex­plor­ing shal­low ar­eas and on pas­sage.

Many cruis­ing cata­ma­rans per­form poorly when sail­ing to wind­ward, although the use of dag­ger­boards, as well as other de­sign fea­tures, has seen sig­nif­i­cant im­prove­ments in this re­spect. It is an es­sen­tial fea­ture to con­sider for any­one look­ing for a per­for­mance cruis­ing cata­ma­ran.

Dis­place­ment should be a se­ri­ous con­sid­er­a­tion for those in­ter­ested in sail­ing per­for­mance, as I know too well from per­sonal ex­pe­ri­ence. At nine tons for her 36ft, my first Aven­tura was on the heavy side and an in­dif­fer­ent sailer in light winds.

My in­ten­tion for Aven­tura II was to have a boat of rea­son­able dis­place­ment, but while the de­signer fol­lowed my sug­ges­tion, the builder had other ideas and she ended up with a dis­place­ment of 17 tonnes rather than the 12.5 tonnes en­vis­aged by the ar­chi­tect, Bill Dixon. So in light winds she was a source of con­tin­u­ous frus­tra­tion.

I was de­ter­mined to get a boat with a lighter dis­place­ment for my third Aven­tura. In­deed Aven­tura III’S de­signed dis­place­ment of 9.5 tons for a beamy 43-footer was as close to per­fect as pos­si­ble and I al­ways made sure to keep her weight down to a rea­son­able level.

Aven­tura IV’S de­signed dis­place­ment was 14 tonnes and even when fully loaded with pro­vi­sions be­haved very well on ev­ery point of sail­ing.

For a long voy­age one should make sure that the main­sail is made as strong as pos­si­ble, with dou­ble, ide­ally triple Uv-re­sis­tant zigzag-stitching and pro­tec­tion patches in the ar­eas where the sail may touch the spread­ers when fully let out. The furl­ing fore­sail(s) should be pro­vided with anti-uv strips.

I have con­sid­ered the sub­ject of the type of main­sail on a cruis­ing boat and have no doubt that a fully bat­tened main­sail, with slab reef­ing, is still the best an­swer for those who are in­ter­ested in per­for­mance. Main­sail furl­ing sys­tems have evolved, and some of the boom furl­ing ar­range­ments com­bine the best of two worlds, by of­fer­ing a quick and easy way to re­duce sail sur­face, and, as the furl­ing main­sail is pro­vided with bat­tens, the loss of per­for­mance is quite min­i­mal.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.