PeterDann
2023-08-14T15:53:03Z
Does anyone know if there is a 'definitive' air draught for a 325?

Or in its absence, would anyone care to mark my homework?

P from owners manual = 11.76m

Waterline to gooseneck = 2.5m

Allow for masthead and instruments = 1m

Total = 15.26m

It's of more than academic interest as I am planning to go under a bridge with charted clearance of 16m tomorrow! Don't worry, with potential clearance of 74cm I am aiming for low water, but even so. I would love a second opinion or two as I hate sailing under bridges...

Thanks!

Peter


Peter Dann

Blue Moon 325/32

MartinH
2023-08-15T08:58:32Z
Hi Peter

I measured our P335 mast when we had it taken down a couple of years ago

Mast foot to top of VHF ariel was 14m

Martin

PeterDann
2023-08-15T18:01:13Z
Thanks Martin.

For the forum/record/posterity: I measured waterline to mast step as 1.5m so this makes 15.5m total. I then reckoned that my allowance of 1m from top of main to top of antenna was a bit over cautious; if we made that 0.75m then my method and Martin's produce the same result: 15.5m. I accept no liability: add your own safety margin!

What I can say is that I made it under the Leven Narrows bridge without bending the antenna but I took at it low water against the last of the ebb so I could do snail's pace. I should have had about 3.5m clearance but I am still terrified of bridges...


Peter Dann

Blue Moon 325/32