Navigation help

[gazpode_l]

Last night, whilst playing my third patrol of my single player GWX campaign I recieved a radio contact just one square north of my position.

The convoy was reported as travelling on a course of SSE and was running at aproximately ten knots.

I've now realised that my navigational skills are questional and need refreshing a little.

I began to draw an intercept line for me to work from so I could work out where to head. But working with a SSE bearing I've now realised I should have plotted the convoy course as being aproximately 160 Degrees, however I have now realised I actually plotted thier course as being 112 degree's.

I did my Sailing "Day Skipper Theory" a couple of years ago and I am wondering I had got my compass rose out, I would have realised my mistake, rather than following an intercept point based on the convoy course of 112' only to then find they were not in the position they should be, which I've realised this morning the reasons being for.

Just trying to get my head around those small incidental bearings (EG NNW, SSE, SSW, NEE etc etc)

Any help/Suggestions to make life easier would be appreciated and would possibly help my yachting theory too.

regards,
Gary
(Aka Gazpode_l)
Playing as: Walter Suhr in U-93

[Pisces]

N = 0
NNE = 22.5
NE= 45
ENE = 67.5
E=90
ESE = 112.5
SE = 135
SSE = 157.5
S = 180
SSW = 202.5
SW = 225
WSW = 247.5
W = 270
WNW = 292.5
NW = 315
NNW = 337.5

All multiples of 22.5 degrees. Read NNE as "north of north-east", so you know that it is 22.5 degrees less (a step backwards along the compass to north) than NE (45) so resulting in 22.5. Or WSW as "west of south-west", which is 22.5 more (one further along the compass) than SW(225) so resulting in 247.5.

You are aware of this drawing technique to develop intercept course?

http://www.subsim.com/radioroom/show...2&postcount=41

[desirableroasted]

Originally Posted by gazpode_l

Just trying to get my head around those small incidental bearings (EG NNW, SSE, SSW, NEE etc etc)

Don't be hard on yourself.

Pisces has listed the exact points for us, which are the ones to use when making your plot. He has also given you an excellent link -- I have that chart in front of me at all times when playing.

But "SSE" in the game means approximately 157.5 heading... it can be 11 points either way, which adds up quickly over a long distance. In addition, contact speed, even when reported at a seemingly precise "9 knots" can be anywhere from 9 to 10 knots. "Fast" "Slow" "Medium" are even more vague.

So even if you plotted an perfect intercept for a 9-knot ship bearing 157.5, it might well be sailing at 10 knots on 167 and nowhere to be seen when you show up. Hydrophones can often bail you out, though.

Also, contacts don't stay on course forever. Single ships tend to follow predictable paths that require turns, and convoys often turn 90 degrees for safety.

[The following may be a GWX thing, I don't remember]

On your navigation map, there is a question mark on the upper-right menu. Hitting it enhances your navigation tools, giving you a compass rose that makes it easier to plot intercepts.

[gazpode_l]

So even if you plotted an perfect intercept for a 9-knot ship bearing 157.5, it might well be sailing at 10 knots on 167 and nowhere to be seen when you show up. Hydrophones can often bail you out, though

I didnt mark it as that though - for some reason I picked 112' (which incidentally is actually S.E.E)

That is where I went wrong - cld be because I was