Originally Posted by islandplanet
Sailboatdata isn't going to help. It usually just gives you I, J, P, and E. As a sailmaker
I can tell you that sailboatdata.com is helpful but it usually doesn't do a great job of listing the various rigs. For instance some boats were manufactured with a standard, short (aka San Francisco), and tall rig. Sailboatdata.com will usually just show one set of measurements.
Never trust a masthead clearance number that you haven't personally verified with a tape measure. Use a metal tape for accuracy. Have someone go aloft and measure how far above the masthead your instruments are. Then hold the tape snug against the masthead fitting while your helper measures down to the water's surface. Remember to add in the figure for the instruments. This will be a slightly longer than actual measurement since you're not going straight down. If you want to make it real accurate, it's some basic trig. You know the hypotenuse and you can get the foot by measuring the lateral distance from the mast to the rail. The other way would be measuring to the base of the mast and then use a string with a level to figure out the point above the water to complete your measuring. Or piece of clear hose with water can help with that as well.
If it's close, I like to hoist a crewmember aloft to verify we're not going to hit. On some boats you can remove instruments.
People will make up there own mind if sailboatdata.com is 'any help'.
I spent 20 years making sails
. In this case, if you are talking about the GULFSTAR
50, the above link IS for the shorter (ketch) rig. The tall mast version can be found here:
GULFSTAR 50 TM sailboat specifications and details on sailboatdata.com
Most of the popular rig options and variations for a particular boat ARE listed.
(though perhaps not in the most user friendly way.)
RE Mast Height-
On sailboatdata.com, I ONLY list a number for mast height above DWL UNLESS one is given on a manufactures brochure or sail plan for a particular rig. I never attempt to 'extrapolate' measurements. These, of course, only represent what a manufacturer or designer
intended on any particular day.
AND, of course, as you have said, you can never be sure about things like bridge clearance without taking your own measurements. (as you would need to do when you order sails
Not that the site is all that great. Errors certainly do exist, information is missing, and the interface is in need of serious work. It's a big list that gets edited every day. I never express an opinion about an particular boat. But I take the RELIABLILITY of the data that you see very seriously.