The 10 second wait !

[derrinurban]

That is the method I use as well.

[Hardigen]

My thanks to you all for the tips and hints . The You tube threads are great Woolfman

[Pisces]

The notepad method relies on accurate range measurement and AOB measurement to get it right. During the speed measurement it only measures the amount the periscope turns while it is locked on the target. From those data it can calculate a knots value. While it is locked on the target, the AOB pointer is kept updated internaly as the lock moves. So that is not the cause

This method has to start with an accurate range. Unfortunately this is difficult due to mastheight errors in the recognition manual, but also due to rendering artifacts. (mast gets clipped from the image because it is thinner the pixels) Also, you need to put the lower line at the right waterline of the ship. It's easy to get the range wrong here. When you are on the surface you can ask your deck officer to provide a range and compare it. But that of course won't help when you are submerged.

AOB is also tricky to read because of perspective changes. It takes effort and practise to get it right estimating it by eye. But when it reaches 90 AOB then the differences are less problematic.

One reason of inaccuracy that can happen during the speed-measurement part of the notepad method, is slight changes in own course due to wave action. If you don't take enough time to allow the bearing to change significantly then the slight wobble in the lock might get it to give the wrong speed. The wobble of the periscope should be a lot less then the amount the periscope turns due to the moving target.

[EDIT] The moral of this story is: try plotting instead, to learn speed and course.

[BillCar]

It should take you 30 seconds to get speed via fixed wire method. Place your UZO or periscope reticule at 000 and angle your bow across the path of the target ship. Once its bow crosses the vertical line of your reticule, start the stopwatch. When the stern crosses the reticule, stop it. Multiply the length of the ship by 2 (1.94 to be precise, but 2 will work), and then divide this number by the number of seconds it took for the ship to cross your reticule. Congratulations, you now have the exact speed of your target, and you can easily reverify every 30 seconds if you want (though once should be enough). Range is inconsequential, and so is the angle of travel – this will work from any AOB to the enemy ship, so long as your reticule is at 000 degrees to your bow.

When starting out, at least, you do need to identify the ship properly to gauge its length, though many types of ships in similar weight classes have similar lengths – i.e., most small freighters are ~75m long. If you get a number that seems way off, make sure you haven't misjudged the length of the vessel.

Sank 120,000 tons of shipping on my last patrol at full realism and with Hitman's GUI mod that doesn't allow for the notepad or stadiametric ranging, so I assure you that this method works. I never bother with the 3m15s method anymore, because I could verify the ship's speed 6.5 times over in that timeframe!

[Hardigen]

Thanks guys for the info, I enjoy the map work and plotting ,the AoB takes some practice and I,m gonna enjoy doin th speed calculations and take care with the range finding .Not use to doin all that ,you think the targets gonna sail away before can let loose a fish . Good hunting to you all. H

[BillCar]

Yeah, just take your time and don't panic – if you think you'll miss the shot, just overtake your target and set up again. No sense wasting an eel if you're not sure!

[Pisces]

I agree, most torpedoes are lost in hastily setting up for a second or belated shot. This pressure is going to mess with your mind.

Good call BillCar. I forgot about mentioning the fixed wire method. Very easy and effective.