What do people do to implement oddball unit situations, such as combat helocopters in civ3 ?

I mean, on one hand I could see using it as a normal air unit. however, being immobile is somewhat silly for a helocopter which can be deployed all over the place, but making it non-immobile means you can park it out in the middle of the ocean for 300 years which is just as silly.

So what do people do?




How about a space-based scenario (star trek/star wars) ?
all ocean or all land? (for purposes of unit movment)

http://www.civfanatics.net/uploads3/Zulu_WRONG_FORUM_animation.gif

I was half expecting that .. forgive my ignorance, but which forum should I have posted it in? I didnt see any which were immidiately obvious :-(