So while we're on the topic of support ships, I wanted to give people some advice.
Have you ever been irritated because you can't perform FRED actions on support ships? Say you're setting up a tense, weapons-tight ceasefire, and if a single fighter shoots even once, the whole thing breaks. It's working like a charm except FFFFFFFFFFUUUUUUUUUUUUUU the enemy just wasted your support ship, which wasn't affected by the ship-protect you were using!
Similarly, what if you want to get the support ship to leave? Or make it stealth? Or give it armor?
Well, you can't select it as an argument for these SEXPs, because it's not on the mission ship list. But what you CAN do is create a when-argument using 'any-of', and then manually add the arguments 'Support 1', 'Support 2', 'Support 3' and so on.
Then set the event trigger as 'when has-arrived-delay <argument>', and perform whatever actions you like (stealth, armor, AI orders) on 'argument'.
You can also use this to perform FRED operations on ships created by Ship-Create, but that's a little more complex, and a topic for next time.