I have a naval combat going on in the Arabian Sea while it is raining. The image below is from the game, 3rd round of naval combat. The NAV A-S factors should be halved due to the rain 3/2=1.5 rounds to 2. However, the initial results, before applying the surprise benefits, show D 2A which is the result you would get with 3 A-S factors. With two A-S factors I would have expected a result of 2A versus the 2.5, round to 3, ships.
Even more interesting is that in the first two rounds of naval combat the NAV was engaged against a single unit in the 4-box, which was aborted in the second round, and the calculations appear to have been correct. I'll post a game file next (just go through and select Naval air for the combat) - I was in the process of comparing the results for a Naval Air versus a Surface when I found this.
