Speed Calculations in seconds using only stopwatch and scope.

02-14-16, 08:44 PM

I really searched the threads before posting this to make sure it wasnt covered elsewhere but this is cracking me up. 3min 15 s rule yes this works great but needs two separate signtings with range estimates (which on the short term ie attack approach are always iffy) and scope needs to go up twice (assuming nobody is actually leaving scope up for the eternity of three minutes 15). Long range tracking obviously the best by taking multiple running map fixes then calculating speed=dist/time. Great during approach end around or shadowing but needs time. Useless on final aproach. Other methods including sin functions with AOB etc are mathematicaly correct , but really! on final approach thats a bit cumbersome.

Does anyone else do it this way.

1. Stop or be very slow <1kt. (you should be anyway with scope up)
2. Up scope
3. Mark on ship bow START watch dont move scope
4. Let ship pass reticule mark on stern STOP watch (the actual pointy part, if AOB is acute estimate where it is as it wont be what you see against the skyline but slightly behind the bulk of the ship.)
5. down scope

speed = ship length/STOPWATCH time.

knots=ship_LOA/STOPWATCH_reading x 60 x 60 / 1852

This is very accurate even with realy bad AOB (which you dont need to know, also range is not important)
It works because despite the range or AOB ships sterns almost always end up going over the exact same point the bow went over (which you dont need to know just its relative bearing because it will be the same point)

I played SH1 and SH2 for years and couldn't figure out how the WOs in SH3 get a great speed estimate in 15seconds to 30 seconds. I thought it was a game cheat for the WO furiously calculating from previous running fixes. Then Duh! I use it myself on my own sailboat and it works great.

If the ship is going so slow it would take 40s to pass and you dont want scope up that long just mark half its lenght in half the time. The faster the ship goes the quicker the reading.

Does anyone else do it this way?

02-14-16, 08:44 PM	#1
Pirate Roberts Stowaway Posts: n/a Downloads: Uploads:	Speed Calculations in seconds using only stopwatch and scope. I really searched the threads before posting this to make sure it wasnt covered elsewhere but this is cracking me up. 3min 15 s rule yes this works great but needs two separate signtings with range estimates (which on the short term ie attack approach are always iffy) and scope needs to go up twice (assuming nobody is actually leaving scope up for the eternity of three minutes 15). Long range tracking obviously the best by taking multiple running map fixes then calculating speed=dist/time. Great during approach end around or shadowing but needs time. Useless on final aproach. Other methods including sin functions with AOB etc are mathematicaly correct , but really! on final approach thats a bit cumbersome. Does anyone else do it this way. 1. Stop or be very slow <1kt. (you should be anyway with scope up) 2. Up scope 3. Mark on ship bow START watch dont move scope 4. Let ship pass reticule mark on stern STOP watch (the actual pointy part, if AOB is acute estimate where it is as it wont be what you see against the skyline but slightly behind the bulk of the ship.) 5. down scope speed = ship length/STOPWATCH time. knots=ship_LOA/STOPWATCH_reading x 60 x 60 / 1852 This is very accurate even with realy bad AOB (which you dont need to know, also range is not important) It works because despite the range or AOB ships sterns almost always end up going over the exact same point the bow went over (which you dont need to know just its relative bearing because it will be the same point) I played SH1 and SH2 for years and couldn't figure out how the WOs in SH3 get a great speed estimate in 15seconds to 30 seconds. I thought it was a game cheat for the WO furiously calculating from previous running fixes. Then Duh! I use it myself on my own sailboat and it works great. If the ship is going so slow it would take 40s to pass and you dont want scope up that long just mark half its lenght in half the time. The faster the ship goes the quicker the reading. Does anyone else do it this way?