Okay one for you to look out for as we've had a few questions about this one
recently.
The 798 order (pick up ships) comes before the 850/860 (Move army type
orders). In the situation where you have two navies at a hex and one army
moves off dropping ships players have been attempting to pick up ships and
if failing. It's not possible to pick up those ships from the army as you
only drop the ships when you move off.
You'd have to anchor/attack/transfer ships orders to get it to work
All orders happen in sequential order... 
Clint