USCG Exam Question: Apparent Wind

[jheldatksuedu]

Originally Posted by C.Karo

OK. The USCG is right. I got out my trusty "maneuvering board" Compass, pencil and parallel rule.
We'll make this easy.
If your sailing due North True at 8 kts. Apparent Wind is abeam off to port at 270deg T, 20kts. True wind will be at 232deg T (or aft of your beam), just over 24kts.
Take a nav class and learn how to use a Maneuvering Board. Its Fun! Also great for relative motion, cpa, etc...

This points out another problem I hadn't considered before, when on a beam reach, is the wind that is abeam, true wind with respect to earth (also with respect to a stationary boat) or apparent with respect to the moving boat, I suspect it may be with respect to the moving boat, since that is the only thing possible for a skipper to "feel." If that is the case, then every boat would have a slightly different direction when on a beam reach for the same true wind vector, since it would develop a different boat speed and slip angle for that same wind and set of it's sails.

Before considerring this my earlier solution would have assumed beam reach is when the wind is abeam with respect to a stationary boat pointed the same direction as the moving boat.

So put that in your pipe and smoke it....

Let's get back to something easy like explaining storm rotation...

[Tomaz473]

Originally Posted by jheldatksuedu

And who decided that north should always be up on a map, why not south???? I suspect if England was in the southern hemisphere, there is a good chance that all our globes would be upside down and south may be up on a map.

Old Portuguese nautical charts had south up on the map.
And Portugal is on the northern hemisphere.

[OldFrog75]

Originally Posted by monte

somewhere within 15 degrees of the beam

Say what?!

Reaching
When the boat is traveling approximately perpendicular to the wind, this is called reaching. A "close" reach is somewhat toward the wind, and "broad" reach is away from the wind (a "beam" reach is with the wind precisely at a right angle to the boat). For most modern sailboats, reaching is the fastest way to travel. On some boats, the beam reach is the fastest point of sail; on others, a broad reach is faster

Beam reach[edit]
This is a course steered at right angles to the wind on either port or starboard tack. This is a precise point of sail, with sails put out at roughly 45 degrees.

Beam reach
(Sport: Yachting)
Definition
To set sail with the wind at right angles to the line of the yacht from bow to stern.

[jheldatksuedu]

I'm starting to like Portugal more and more, Not that I think south should be up, it really doesn't make any difference, but it was pointed out in another thread that they are one of the few countries that have learned that prohibition does not work. They basically legalized drugs over a decade ago, and have had very good results with it. I never have used a drug and never will but I suspect there isn't a person in a civilized country on earth that has not been negatively affected by the violence and crime associated with drugs being illegal. I certainly have been affected by crime big time, to the tune of a 1/3 of a million.

[jheldatksuedu]

Originally Posted by OldFrog75

Say what?!

Beam reach[edit]
This is a course steered at right angles to the wind on either port or starboard tack. This is a precise point of sail, with sails put out at roughly 45 degrees.

Beam reach
(Sport: Yachting)
Definition
To set sail with the wind at right angles to the line of the yacht from bow to stern.

Apparent wind or true wind at the right angle, that's the, "say what"

It's not going to make a big difference, but a difference it will make, by about 3 or 4 degrees. When they say precise point of sail, something needs to be more precise.......

[OldFrog75]

Originally Posted by jheldatksuedu

Apparent wind or true wind at the right angle, that's the, "say what"

It's not going to make a big difference, but a difference it will make, by about 3 or 4 degrees. When they say precise point of sail, something needs to be more precise.......

I was commenting on Monte's statement that a beam reach is within 15 degrees of the beam....

[Stu Jackson]

Originally Posted by OldFrog75

That's how I read it and came up with #4 as the obvious answer as well but after reading the posts here I'm questioning my understanding of True vs. Apparent wind when sailing on a beam reach. I always assumed the definition of a beam reach was 90 degrees off of True but after this debate I'm not so sure anymore.

I thought all points of sail were defined as relative to True wind...

We had this discussion about, oh, six months ago. IIRC, the conclusion, after the usual loooong debate, was that the diagram that Monte posted was with a boat that was standing still!!!

Many of us posted that a beam reach to us is using apparent wind.

As far as this thread is concerned, IIRC the original CG question stated that. I'll go back and look and then edit this.

EDIT

yes, apparent: on a beam reach in an apparent wind of 25 knots.

[Cadence]

Originally Posted by carstenb

I must have been asleep when i answered. Please disregard my answer

I do know better
(Ashamed)

That is alright Carsten, I apologized for one the other day. Snap answer. I guess we aren't perfect like some but at least own up to it. I still stick with the index finger wet in your mouth and held up. The law of sines would do but how cares what the wind reading is kns. will be.

[OldFrog75]

Originally Posted by Stu Jackson

Many of us posted that a beam reach to us is using apparent wind.

EDIT

yes, apparent: on a beam reach in an apparent wind of 25 knots.

Granted I didn't do an extremely thorough search, but I didn't find any definitions of beam reach as relative to apparent wind.

I read the problem as sailing on a beam reach perpendicular to True wind and coincidentally with 25 knots of apparent wind, not sailing on a beam reach perpendicular to apparent wind. Everything else followed from that assumption.

I guess I got the right answer for the wrong reason.

[Stu Jackson]

Originally Posted by OldFrog75

Granted I didn't do an extremely thorough search, but I didn't find any definitions of beam reach as relative to apparent wind.

I read the problem as sailing on a beam reach perpendicular to True wind and coincidentally with 25 knots of apparent wind, not sailing on a beam reach perpendicular to apparent wind and everything else followed from that assumption.

I guess I got the right answer for the wrong reason.

At the risk of starting that old discussion up yet again, I did some research in Sailing for Dummies. In all their descriptions there is NO mention of apparent or true wind.

However, all of their diagrams show the boat MOVING, so one could INFER that it meant apparent wind.

The best way I can think of to deal with this "is a beam reach based on apparent or true wind?" silliness is to note that close hauled almost always means to me apparent wind, 'cuz as mentioned in that previous discussion, it's all we can sail by and with (unless one has expensive instruments to measure true wind, which IIRC get used by die-hard racers for strategic and tactical reasons). They still TRIM to the apparent wind.

Have at it, me hearties.

[OldFrog75]

Originally Posted by Stu Jackson

At the risk of starting that old discussion up yet again, I did some research in Sailing for Dummies. In all their descriptions there is NO mention of apparent or true wind.

However, all of their diagrams show the boat MOVING, so one could INFER that it meant apparent wind.

The best way I can think of to deal with this "is a beam reach based on apparent or true wind?" silliness is to note that close hauled almost always means to me apparent wind, 'cuz as mentioned in that previous discussion, it's all we can sail by...

Have at it, me hearties.

Ok except that close hauled is a sail trim that produces the highest point of sail, not a point of sail in and of itself.

One of the better sailing trivia questions...

[med]

The usual definition of a beam reach is that the true wind direction is at exactly 90 degrees to your heading (not course over ground).

In this case, the apparent wind direction is ahead of the beam, and a bit stronger.

Then of course response (1) makes no sense - which is a hint that may be their definition of beam reach is that the apparent wind is at 90 degreese to your heading.

I think it is very bad practice to use terminology in a way which is different from that which most sailors use, and also not to define what that nonstandard terminology means.

They should shoot the guy who drew up the questions.

[Stu Jackson]

Originally Posted by OldFrog75

Ok except that close hauled is a sail trim that produces the highest point of sail, not a point of sail in and of itself.

WADR, that appears to be wrong. How can that be when all the rest of the points of sail are described/defined as related to the wind direction, too?

[OldFrog75]

Originally Posted by Stu Jackson

WADR, that appears to be wrong. How can that be when all the rest of the points of sail are described/defined as related to the wind direction, too?

What is CLOSE-HAULED?
In admiralty law, this nautical term means the arrangement or trim of a vessel's sails when she endeavors to make a progress in the nearest direction possible towards that point of the compass from which the wind blows. But a vessel may be considered as close-hauled, although she is not quite so near to the wind as she could possibly lie. Chadwick v. Packet Co., 6 El. & Bl. 771



Law Dictionary: What is CLOSE-HAULED? definition of CLOSE-HAULED (Black's Law Dictionary)

[monte]

OF, Im sure theres a ton of different ways to explain sailing angles and a lot of difference of opinions especially in online resources. Unfortunately when I learnt to sail we had no acurate way to tell if the true or apparent wind was at exactly 90 degrees to the yachts heading. Maybe you had a higher tech dinghy than me :P A beam reach to me means the wind on or about the beam as per the pic I posted and as per the following interweb snippet:

Nautical. a point of sailing in which the wind is within a few points of the beam.