Active Sonar Example

[georges]

Sorry, me again. I find examples are the best way to understand rules but the example on Active Sonar (5.5.1) puzzles me.

I understand and follow it all, but don't understand why the sonar would get a T1 rating if it succeeded in the dice throw. Firstly if it had got modifiers of -1 (better than the -2 it received) it would have automatically got a T0. So for a worse situation it may get a better result. Also rules 5.0.1 B suggests that the dice throw option are for Operational and Tactical zero results, but here we are throwing for a Tactical one result.

Is this a typo or are there other factors afoot that I am not aware of?

George

[williammiller]

For sonar detection there is *always* one die roll required (the one on Table 5.5 to determine the adjusted base range), but in some cases you may require a second 1d10 roll on Table 5.10. Please note that rule 5.0.1 B is referring to a possible roll on Table 5.10, not the roll on Table 5.5  --  I think in this case you may be confusing the two rolls?

In the specific case you have a T0 range sonar and roll a 1 through 4 on Table 5.5 [ i.e. you get the (3), (5) or (8) result ] then all modifiers for the detection are applied to the "1d10 ODDS" section on Table 5.10 Net Detection Range as a +/- column shift. An example to help make this clear:

Lets say we have a unit with a T0 sonar attempting a active detection of a submarine. The player wolls 1d10 on the "T0" column on Tabel 5.5 and rolls a 3 ; this results in an adjusted detection rating of a [8]. Let us assume the modifiers for the detection attempt (from Table 5.5.1.1) total a -3 . Indexing the [8] adjusted rating with a -3 modifier on Table 5.10 we see that we have a Net Detection Rating of a [2]...this means we have to roll a 2 or less on 1d10 to detect the target at range T0...if you fail this roll, or the target is greater then T0 range distance then you will not detect it.

Note that you also may require a second roll (derived from Table 5.10) even if the sonar range is greater than T0 but the modifiers from the detection attempt are high enough to push the net range into some of the lower columns - for example, if you have a sonar with a adjusted base range of T2 but the net detection modifier was a -6, if you index the T2 range with the -6 modifier on Table 5.10 you get a net detection range of [3], which means you have to roll a 3 or less on a 1d10 roll to detect the target at a T0 range.

I hope the above helps...

[georges]

Thanks that helps as another example that helps my understanding. However the example I am looking at is not the one you state. The one in 5.5.1 in my version of the rules concerns a Spruance attempting to detect a sub at 2 holding box range. The active rating is T1. The dice roll on Table 5.5 is a 3 which gives a T1 result. (First die roll.) The modifiers are totaled to be -2. Therefore on Table 5.10, indexing T1 with -2 we get a result of [6]. The text then states that if a 1 to 6 is rolled (second die roll), the destroyer would detect a submarine at T1. (But could not detect the sub at 2 range.) My query is about the interpretation of the die result, specifically the T1 given if it passed the test. Surely this should be a T0 result? It makes no difference to the result in this case, but would have done if the sub was closer.

George

[williammiller]

George - Ahh, yes - the relevant part of the example using the Sprucan should read:

"Indexing the T1 adjusted range with the -2 total modifiers on the 5nm section of Table 5.10 we obtain a detection range of [6]; this means we must roll
a 6 or less on 1d10 to detect the target in the same box (T0). Since the target submarine is 2 holding boxes away (T2) we cannot detect it."

I do have this in my errata folder, I need to update the errata document and post it.

[georges]

Great thanks.