Mast height - measured from where?

[leftbrainstuff]

Several measurements. It depends on...

1) actual mast length of the aluminum extrusion which applies if shipping or ordering a new mast.
2) P - distance from boom to halyard sheave of the main. Sail track related.
3) bridge clearance which includes whatever is at the top of the mast and will vary depending on tide and your actual waterline.
4) Standing rigging related which you use in calculating mast column buckling bending flexural strength, amount of swept back, etc.

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[Olde Chief]

Mast length or height will vary as to what you are doing. Replacing the mast, replacing the sail track, whether you it is keel stepped, deck stepped, and how much mast you want above the topping lift sheaves.. However I would recommend that you will save your self a lot of head aches (mentally and physically) if you have a professional rigger do the ordering and installation...

[TeddyDiver]

Originally Posted by GordMay

DWL is the designed water line, when the boat is loaded to its designed capacity.

Actually half loaded, thou it's not a big difference..

[Cheechako]

For track length, attach your 100 ft tape measure to the halyard and pull it up to measure. You DO have a 100ft tape right?:>)

[Sinbad51]

If you are looking to replace your mast track, you are looking for the max mainsail hoist above the boom. That is referred to as your "P" measurement. If you don't have it in your documentation for your boat, if you contact any sail maker, they can supply you with it.

[Wotname]

Originally Posted by Cheechako

For track length, attach your 100 ft tape measure to the halyard and pull it up to measure. You DO have a 100ft tape right?:>)

Will ten tapes each 10' do?


Opps... wrong thread, now where is that thread about titles we would like to see

[wesevans]

DWL means that you measure from the design water line.

[markpierce]

Nearly 32 feet from the waterline. Mast is perhaps 24 feet above the roof. But one also needs to consider the anchor light, VHF antennae, and the lightning rod.

[Stu Jackson]

And if your boat isn't fully laden, the mast will be higher, right?

Even with all the cr*p I have on board, with tools and food and other spares, I still float HIGHER than the designed waterline.

Hmm, less wetted surface???

[Delafontaine]

Better check the accuracy of a 100ft tape ! Years ago, we had a nasty surprise when challenging the "P" measurement of our new main sail made at Gowen Ocean Sailmakers Ltd 0f West Mersea (England).
Our reinforced plastic tape was over 30 cm (1 ft) short compared with the reference steel tape of the sailmaker.