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New here,, great info that has helped me a lot!!just purchased SH4 and glad i did!!
i,m reading all the tips here and learning a lot! one question i do have is ....how do i use the compass that is on the chart?? it,s above the ruler,dividers,eraser,etc....when i click on it ,,it flips open and flips back closed with another click...can,t get it to do anything,,,not even readable???
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flipping the compass open enables a compass rose to appear when using the ruler navigation tool. It's very handy for plotting the course line of a Tgt when you have figured it out. if you are using automatic targeting, and drawing the course line, you can use the compass to accurately plot the target course
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DECKS AWASH
"Decks Awash" (DA), as used here, means to operate at the deepest depth that the diesels will run continuously . The advantage in doing this is that, when compared to being fully surfaced, much less time is needed to disappear below the waves. If a threat appears, go to DA early and avoid being pounded (or sunk) as you wait, and wait, and wait, to submerge.
Running DA is mainly useful to avoid air threats. If battery recharging is critical and aircraft might be near you can safely recharge until the aircraft are spotted before quickly diving. Or, if you have radar, you can surface to DA and check for enemy aircraft before coming completely up with the comfort that if aircraft are present, they can still be avoided with a quick dive. With practice you will find other times DA is a lifesaver (rescuing downed airmen with enemy guns nearby, etc).
Two important points must be remembered, to use DA successfully. First, the critical depth for running at DA is often different between classes of submarine. Second, the critical depth for the diesels is usually deeper than that for CO2/O2 exchange and using the deck gun. This means CO2 can build up inside the sub. So there is a second DA to remember, DA(CO2). It, too, varies between sub classes but as a rule, it's 2-3 feet less than DA (diesel). DA(CO2) is always the same as the critical depth for using the deck gun, or DA(Gun), so the two can be combined.
Below is a guideline which lists the critical depths for DA(diesel) and DA(CO2/Gun) for the different classes of sub in SH4. [Measurements were made at flank speed, in calm seas, with 100% battery charge.]
DECKS AWASH DEPTH IN FEET FOR SUB TYPES
TYPE BOAT.........DA(diesel)........DA(CO2/GUN)
GATO.....................28...................26
BALAO....................28...................26
GAR.......................32...................26
PORPOISE...............28...................23
SALMON.................31...................26
NARWHAL...............30...................28
S-42......................26...................26
S-18......................26...................26
As a rule, 28 feet is a good rough guide for DA(diesel), unless you're in an "S" boat (where it's 26). "GAR", "SALMON", and "NARWHAL" classes can run slightly deeper. For DA(CO2/Gun), 26 feet is a good guide for getting rid of CO2 for all boats except the "PORPOISE" class, where it's 23 feet, and the "NARWHAL", where it's 28.
The time needed to reach periscope depth is affected by 1) the depth at which the "dive" order is given, 2) the dive depth ordered ("periscope depth" vs "CRASH DIVE!". "CRASH DIVE!" is always faster. But to avoid suicide, remember that ordering "CRASH DIVE!" takes you to 110 feet. Without that much water under you, you will die, unless you can successfully change the order (after submerging) before hitting bottom. Use "CRASH DIVE!" with caution.
Below are dive times (in seconds) between classes of boats for the order "periscope depth", fully surfaced and at DA(diesel). Times to reach periscope depth on ordering "CRASH DIVE!" will be faster. [Times were obtained at flank speed, in calm seas, with 100% battery charge.]
TIME TO REACH PERISCOPE DEPTH
TYPE BOAT......SURFACED............DA(diesel)
GATO..................120.....................23
BALAO..................80.....................29
GAR....................120.....................23
PORPOISE..............85.....................24
SALMON..............107.....................26
NARWHAL............125.....................24
S-42....................72.....................47
S-18....................72.....................47
The difference between dive times is dramatic, and clearly shows the advantage of running at decks awash when a fast dive is important. It should be remembered that the DA strategy doesn't work in rough seas, where the electric engines will cut on and off, discharging the batteries.
Also remember that you get poor fuel efficiency (fewer MPG) and lower speed when running at Decks Awash since you are, after all, partly submerged.
(Incidentally, "CRASH DIVE!" from DA(diesel) will reach periscope depth for all boat classes in 17 seconds, except the NARWHAL class which makes it in just 14. Now that's a fast dive!)
NB: The above pertains only to SH4 and does not reflect the performance of historic submarines.
(OK by you Tambor198 for the SH4 Guide?)
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