# Finding declination/variation

Leads to a discussion on "Ferry Angles"

No Problem
I’m glad you went to the effort, because it was very clear and easy to understand, especially compared to what I wrote.

I agree and well done Nate

Very good info there
On big vessels and in USCG exams a maneuvering board is used to work out a variety of complex nav problems, but the approach shown on the link is excellent and easy.

going to be out there for 10 hrs./day …
… the next three , Chesapeake , probably cover the whole mid bay area .

Looks like

– Last Updated: Apr-30-10 8:05 AM EST –

you might be needing your "flight computer" from the airplane. (They still use those, right? The little circular cardboard things and the ruler with attached protractor?) That seems like a lot of time on big water to me.

To know where you are, judging by the considerations that have been raised so far, you'll need to set a heading to compensate for wind (and tide/current) drift and achieve a desired course... just as you do in an airplane.
Nate sure did a good job of putting into words something we (or at least I) don't think about all the time. Very nicely done and thank you.
Its like the quarterback throwing a football; He does it, practices it, gets good at it. Yet I'll bet it never crosses his mind that he should be calculating the degrees above the horizontal of the throw, angle of the wind and angular force it exerts on an object with the mass of a football, traveling at a velocity, no an acceleration, of - will it ever achieve a terminal velocity?- to arrive at a location where the receiver, traveling at some heading at some feet/sec, will be.
Doesn't matter cuz' he's been sacked.

I don't paddle big water as much as many here apparently do, but don't most of you paddle a little into the wind/current when you're taking it on the side, to one degree or another? (Helps not to be perfectly sideways to the wave direction anyhow...) Isn't that really a heading compensation to achieve a desired course? Like aiming upstream of your desired mark when crossing a river current? Gets to be sort of instinctive. We really don't need a lot of trig to do it.

Speaking of drift... that doesn't have a lot to do with agonic lines or the earth's shifting magnetic field as Declination/variation considerations do, or am I missing something?