What happens if my marine troop transports encounters a stack of enemy troop transports?

Can enemy transport ships pass each other on a grid line?

Can a transport ship blockade a port?

Situation is early game where no one has developed corvettes or strike aircraft and 'Viva Cuba Libre' is my motto.

On a side note ... why can't my fighter aircraft attack transports?

What do I know so far ... transports are vulnerable to Corvettes. If they are on the same grid line and moving toward the Corvette they 'attack' the Corvette ... so the Corvette shooting and their feeble ramming attempts (which now apparently do no damage) conspire to sink them fast.

Transports are faster than Corvettes ... so if they are moving away from the Corvette, they escape.

I still don't know what happens when transport meets transport. I have one instance where an enemy transport met my transport loading at the dock and it appeared to stop. The enemy was subsequently destroyed by a nearby Corvette.

However, the enemy forces on the island were augmented (overnight whilst I was sleeping) by two additional battalions of motorized infantry ... and I don't know how they got there as I had both ports covered.

Strike Fighters do a grand sum of 1/12 damage to a given transport carrying a motorized battalion. I was expecting more.