SUBSIM Radio Room Forums - View Single Post - Speed Calculations in seconds using only stopwatch and scope.

Pisces · 02-17-16, 04:27 PM

Aside from not turning the scope, you should also be sure the boat itself is not turning. So "rudder amidship".

You can have a bit of speed, but then the scope must be pointing to 0 degrees or 180. And the boat must be turned so the scope is in front of the target beforehand to do this. Then your speed doesn't influence the result.

If you work out those divisions and multiplications then you'll find that you must multiply by 1.94 (=3600/1852) to get from meters per second to knots. So multiplying by 2 is just too easy and accurate enough.

Even doable in your mind.

02-17-16, 04:27 PM	#4
Pisces Silent Hunter Join Date: Dec 2004 Location: AN9771 Posts: 4,904 Downloads: 304 Uploads: 0	Aside from not turning the scope, you should also be sure the boat itself is not turning. So "rudder amidship". You can have a bit of speed, but then the scope must be pointing to 0 degrees or 180. And the boat must be turned so the scope is in front of the target beforehand to do this. Then your speed doesn't influence the result. If you work out those divisions and multiplications then you'll find that you must multiply by 1.94 (=3600/1852) to get from meters per second to knots. So multiplying by 2 is just too easy and accurate enough. Even doable in your mind.