Definately not a pro at the game but here are some tips and lessons learned that may help you out in the campaign.

• As often as you can, send scout planes around the areas of your island.
• In a submarine encounter where you are the attacker
  • Best results occur if you have more than one sub attacking (think wolfpack)
  • Once you fire your torpedoes
    • change course and depth and run silent.  Don’t worry about reloads…the AI seems to know exactly where you are
    • Click on the Retreat button.  This will give you 180 seconds before you can exit.  If the DDs find you, click exit.  Otherwise, plan a second attack.
• In a submarine encounter where you are the defender
  • Immediately change course with your capital ships and cruisers
  • Break off your DDs from the group and send them in arcs ahead of your fleet.
    • Look for disturbances on the water surface…these are incoming torpedoes!
    • Send your DDs in the directions that the torpedoes came from
    • Japanese subs will likely be 4000 – 5000 yds away from where you start.
    • Keep one DD running slow to hear better when hunting subs
• Guadalcanal
  • DO NOT send troops directly to Guadalcanal at the start.
  • Build up a staging base nearby and then proceed to land on Guadalcanal
  • Keep an ongoing air patrol around Guadalcanal and “the Slot”
  • Station many submarines in “the Slot” and waters north of Guadalcanal to interdict convoys and enemy warships.
  • Keep a carrier group nearby “the Slot”
    • Once Submarines locate and engage groups, follow up with air strikes to finish them off (if possible)
• Japanese submarines are of two types…both which carry floatplanes.
  • If you spot a floatplane (or get spotted by one), there is likely a submarine nearby.
  • Launch anti-submarine air patrols in the area immediately.
• Japan has the uncanny knack of landing troops at bases at night when you can’t cover the area by air.
  • Most landings are cargo ships escorted by two destroyers
  • Keep a small cruiser force with DD escort around bases you wish to defend. This should be enough to stop the landings.