Question about naval combat

[explorer2]

With land units, when you move a unit into a hex where there's an enemy unit that was invisible due to your low recon/its high hide value, you have an automatic round of combat. This can be deadly if you're not prepared and you have small units.

1. In naval combat it never seems to work that way. When I enter a hex where I thought no sub was present, the sub then appears, but no combat occurs.
Is this hard coded? Is there any setting to change this?


2. Regarding rule variants: In the Editor, In Settings:RuleVars: RulevarGroups, when selecting a subheading, like Movement types & Ranges, several numbered rules show up to the right.
When looking at these numbers, there are more numbered rules that appear in all the screens (over 600)
Where do these rules come from? Is there a way to view them all somewhere? Are these rulevars something Vic created and in a file somewhere so that I can add other ones than those seen currently?
I'm clueless about this aspect.

Any help on either of these questions greatly appreciated.