It's worse than that.
Dory (and maybe bateaux) builders reckoned their boats by the length of the
bottom planks. If there's a bowsprit or boomkin or overhanging boom, the
extreme length of that mess is Length Overall (LOA) or 'sparred length'.
Hull designers talk about length between perpendiculars, which is the length
of the hull, not including protrusions, sometimes called length on deck
(LOD)..

So, pick the one taht serves your purposes. If you're reserving dock space,
it's LOA. For most purposes, LOD is indicative. For your local assessor,
LWL or even bottom length might be worth a try.


"David Manthey" wrote in message
...
Is there an official way to determine the length of a boat?

For instance, I am captain of a wooden bateaux that the builder
claimed was 23' long. Measured from the very rear of the sternpost to
the very forward of the stem, it is 23' 9". Measured at the height of
the gunwale and including the stem and stern posts, the boat is 23'
0'. Exclusive of the stem and stern posts, the boat is 22' 6". The
typical 'fullen laden' water line is 21', while the length along the
bottom (it is flat bottom, so has no keel), is 19' 6".

So, my questions a (a) when telling someone the length of the boat,
which number do I use, and (b) has there been any standard on this
over time?

Thanks much.

- David
David Manthey

Orbitals - Programs - Books - http://www.orbitals.com

Dories were traditionally measured along the gunnel. A "16 foot dory"
measures only about 14 feet LOA when following industry standard measurement
rules for LOA (do not include bowsprits, rudders, swim platforms, motors
etc, just measure the hull.) Designers also use this definition of LOA, but
there's a reason why... it's the legal definition.

Brian D



"Jim Conlin" wrote in message
. ..
It's worse than that.
Dory (and maybe bateaux) builders reckoned their boats by the length of
the
bottom planks. If there's a bowsprit or boomkin or overhanging boom, the
extreme length of that mess is Length Overall (LOA) or 'sparred length'.
Hull designers talk about length between perpendiculars, which is the
length
of the hull, not including protrusions, sometimes called length on deck
(LOD)..

So, pick the one taht serves your purposes. If you're reserving dock
space,
it's LOA. For most purposes, LOD is indicative. For your local assessor,
LWL or even bottom length might be worth a try.


"David Manthey" wrote in message
...
Is there an official way to determine the length of a boat?

For instance, I am captain of a wooden bateaux that the builder
claimed was 23' long. Measured from the very rear of the sternpost to
the very forward of the stem, it is 23' 9". Measured at the height of
the gunwale and including the stem and stern posts, the boat is 23'
0'. Exclusive of the stem and stern posts, the boat is 22' 6". The
typical 'fullen laden' water line is 21', while the length along the
bottom (it is flat bottom, so has no keel), is 19' 6".

So, my questions a (a) when telling someone the length of the boat,
which number do I use, and (b) has there been any standard on this
over time?

Thanks much.

- David
David Manthey

Orbitals - Programs - Books - http://www.orbitals.com