Bridge clearance
- Thread starter Wbpirate
- Start date
The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
All boats will likely be a little different. You need to measure it yourself. Then measure it a couple more times to be absolutely sure. Then add a few inches for salinity, fuel, water and storage variables. You want to know for yourself what it is rather than the internet.
catalinajack
Guru
Good advice. Measure it yourself. If you need an example of why, just go on YouTube and search "the can opener bridge". After measuring my boat and adding four inches as a safety factor, I made a leldger pole the fits into a burgee mount on the forward-most point on the bow. It measures to the exact height, plus four inches, of my boat with an extension for two different heights, one with and one without the radar arch down. If there is any doubt about clearance, I can approach a bridge at dead slow speed and back out if the pole strikes the bridge.
Have a friend whose production sailboat has a well known bridge clearance. Despite that, the Windex on the masthead was bent, due to contact with the underside of a bridge.
Yours will vary. Measure it yourself.
mvweebles
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Anyone have the best way to measure bridge clearance? I've been thinking of laying a 2x4 horizontally across the canvas/hard-top and get it as level as possible. then measure to the waterline on both sides (average the measurements just in case it's not level). Then measure from 2x4 upwards to highest point.
Not exactly rocket science, but any better ideas?
Peter
Not exactly rocket science, but any better ideas?
Peter
Benthic2
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Comodave
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On our previous boat I measured the height with a 12’ straight edge and a Sharpie taped to the end. Held it on the highest point and a level. Fortunately we were in a covered slip so I could make a mark with the Sharpie on one piling. Then just took a tape measure from the mark to the waterline. Works easily if you are in a covered slip.
Giggitoni
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That’s what I did, Peter. I used a small bubble level to be reasonably sure of level, measured to water and up to mast anchor light with a steel tape and added the two together.
I used a tape measure from the top of the mast down to the deck. Then from deck to gunnel then to waterline. Add them up. I could do fun stuff like trig and geometry but think this was most accurate. You can use something for a straight edge to account for a curved deck and subtract inches when the subsequent measuring point is higher than the previous point, like where a gunnel might be higher than a deck. Just simple math, no cosine or Pythagoras or batteries needed.
jleonard
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That’s pretty much how I measured mine.
Easy to do. We hen made a sketch with numbers on it and put it in my log book.
Easy to do. We hen made a sketch with numbers on it and put it in my log book.
I goofed around with a laser level to measure my motorhome parked next to my garage
it was above the gutter line up onto the shingles.
+ my laser wasn't really the best, needs to be manually leveled, and teh precision of the bubble in it is quite low.
it was really a sketchy thing....
I also tried measuring each step...highest point to the roof, then the roof down to the ground....also very sketchy, with the radius corners, slopes, etc... harder to do than it seems like it should be.
I think with a better laser...one of those really nice self leveling ones, then it probably gets a lot better....if you can pull up next to a piling or structure. Otherwise seems like MVweeble's 2x4 straight edge might be a decent approach. I think using a bubble level and measuring it only one one side introduces room for error.
it was above the gutter line up onto the shingles.
+ my laser wasn't really the best, needs to be manually leveled, and teh precision of the bubble in it is quite low.
it was really a sketchy thing....
I also tried measuring each step...highest point to the roof, then the roof down to the ground....also very sketchy, with the radius corners, slopes, etc... harder to do than it seems like it should be.
I think with a better laser...one of those really nice self leveling ones, then it probably gets a lot better....if you can pull up next to a piling or structure. Otherwise seems like MVweeble's 2x4 straight edge might be a decent approach. I think using a bubble level and measuring it only one one side introduces room for error.
wkearney99
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Newfangled ones include both distance AND angle. https://www.amazon.com/s?k=laser+di...ngle+distan,aps,54&ref=nb_sb_ss_ts-doa-p_1_18
COD
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Does anyone know the height from the keel to the bridge on a 36 GB? Considering putting her on a trailer if possible to get from MA to VA as research tells me it's not a trip to be made until spring. Mast will be down and bimini and windshield can be removed and they will tilt it slightly towards the bow on a trailer to get a few more inched from the highest spot which would now be the engine controls. Maybe my search skills are diminishing but I've been all over the net and that's the one spec that is elusive.
Cigatoo
Guru
From the owners manual GB 36 Classic Hull 715
Attachments
Cigatoo
Guru
You are welcome. Good luck with your new boat.
It is an elusive spec, but for purposes of actually clearing bridges may be a dangerous one. You must measure your own boat. Measure with and without electronics. Measure with and without full loads. Then you can build a book of useful information.
Cigatoo
Guru
I agree with the above. However he wants to go over the road. That is a whole different story. Any boat mover worth their keep should be able to help him with this as trailers add a whole different dimension.
Very true.
