GNAV...

   Who invented the GNAV??
Was it the 4 tonners or the 14s??
Is this a unique example of SMODs leading development?

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Blobby Send Private Message Find Member's Posts Really should get out more Joined: 07 May 04 Location: Australia Online Status: Offline Posts: 779	Post Options Post Reply Quote Blobby Report Post Quote Reply Topic: GNAV... Posted: 01 Feb 05 at 9:25am
	Who invented the GNAV?? Was it the 4 tonners or the 14s?? Is this a unique example of SMODs leading development?

Chris 249 Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 10 May 04 Online Status: Offline Posts: 2041	Post Options Post Reply Quote Chris 249 Report Post Quote Reply Posted: 01 Feb 05 at 10:21am
	Well, I thought it was in the 49er before either, wasn't it?? But the real winner, AFAIK, is of course the boat that had fully batten roachy sails, 100lb (or so) hulls, cam cleats, singlehanded spinnaker set ups, sliding seats, planing hulls, hollow masts and high performance in the 1800s....the International Canoe, of course. A piece in the US Canoesletter a while ago included a shot from Y&Y of the early '80s (IIRC) showing and describing a GNAV on a British canoe back then; several years before the 4000 or 49er arrived and (from the caption and other info) well before 14s had them (if they do). Let's face it...if it wasn't invented in a canoe or the NZ R Class, it just wasn't invented..... Edited by Chris 249

Pierre Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 15 Mar 04 Location: United Kingdom Online Status: Offline Posts: 1532	Post Options Post Reply Quote Pierre Report Post Quote Reply Posted: 01 Feb 05 at 10:35am
	Dumb question maybe, but is there any performance difference / issues between a traditional vang and gnav. What's the upside and downside?

catmandoo Send Private Message Find Member's Posts Visit Member's Homepage Really should get out more Joined: 16 Mar 04 Online Status: Offline Posts: 545	Post Options Post Reply Quote catmandoo Report Post Quote Reply Posted: 01 Feb 05 at 12:27pm
	The gnav is up Vang is down ! Sorry , couldn't resist it


Dead Air Send Private Message Find Member's Posts Groupie Joined: 27 Dec 04 Online Status: Offline Posts: 80	Post Options Post Reply Quote Dead Air Report Post Quote Reply Posted: 01 Feb 05 at 12:48pm
	lots more space for the crew with a gnav...

Granite Send Private Message Find Member's Posts Visit Member's Homepage Far too distracted from work Joined: 12 May 04 Location: Scotland Online Status: Offline Posts: 476	Post Options Post Reply Quote Granite Report Post Quote Reply Posted: 01 Feb 05 at 1:36pm
	One problem with them is that they are not weighed with the boat meaning that because most open rule classes restrict only hull weight if you have a gnav your boat has a heavier sailing weight than if it does not. Untill you could make them light enough for the ease of use advantages to outweigh the weight penalty they were not poplular in the development classes.
	If it doesn't break it's too heavy; if it does it wasn't built right

Yann Send Private Message Find Member's Posts Newbie Joined: 24 Jan 05 Location: United Kingdom Online Status: Offline Posts: 28	Post Options Post Reply Quote Yann Report Post Quote Reply Posted: 01 Feb 05 at 1:54pm
	Potentially more mastbend introduced by the gnav as its presses forward on the mast higher up. Anyone know the facts on this? Its probably in Bethwaites book but i dropped that on my foot once and now im too scared to pick it up.

Matt Jackson Send Private Message Find Member's Posts Really should get out more Joined: 21 Sep 04 Location: Darlington Online Status: Offline Posts: 962	Post Options Post Reply Quote Matt Jackson Report Post Quote Reply Posted: 01 Feb 05 at 4:31pm
	I think the amount of mast bend will be the same wherever you press - it's the mechanical advantage that changes (it gets easier) but that's the same for any system. It's the old effort-required versus rope-in-the-boat question. I'm sure someone will tell me I'm talking rubish... and not for the first time
	Laser 203001, Harrier (H+) 36

Twin Poles Send Private Message Find Member's Posts Newbie Joined: 06 Nov 04 Location: United Kingdom Online Status: Offline Posts: 33	Post Options Post Reply Quote Twin Poles Report Post Quote Reply Posted: 01 Feb 05 at 7:03pm
	I think one advantages of the gnav system is that it allows you to control the mast bend low down by ballancing the push from the gnav and the pull from the lowers.

Bruce Starbuck Send Private Message Find Member's Posts Posting king Joined: 14 Sep 04 Location: United Kingdom Online Status: Offline Posts: 124	Post Options Post Reply Quote Bruce Starbuck Report Post Quote Reply Posted: 01 Feb 05 at 8:05pm
	Matt - You're talking rubbish! The mast bend forces induced by the boom/gnav/vang arrangement have to be higher up with a gnav than with a vang, surely?