As argus said, truk lacks, well, anything, in the stock game except one "historical" battle. Of course in the "historical battle" the US fleet steams through the anchorage, lol.
http://www.subsim.com/radioroom/showthread.php?t=116283
^^^ link to my campaign. It's JSGME compatible.
Beware. The stock game doesn't include reefs. Truk, and many other important
anchorages used by the IJN (USN, too) were protected by reefs with limited access via gaps in the coral reef. Because this was so critically import, I made my own reefs using the only tool available---sub nets.
So be careful cruising in the Marshalls and Carolines. Various places have "reefs" now, and the only way in is through one of the channels. You'll have to google real maps to see where they are, or watch japanese shipping and see where they go.
tater