Your top speed is limited by the slowest ship in your fleet, freighters, troop carriers, submarines, etc. The message 'There is Land in the way' will be displayed anytime you try to cross a land mass during fleet manuevers. Answer Yes to confirm the fleet movement after setting your course. P.T.O. Japan has the logistical and offensive advantage at the start of the game, but lacks the resources and raw materials to keep up a sustained war effort. The Allies lack logistical and tactical advantages but have access to resources and material to fuel a sustained military effort once their industrial potential is harnessed.
Technology is critical.
Midway, Wake, Truk, and the Marshall islands are crucial mid-Pacific bases. You must also have sufficient materials at bases where ships may be repaired. Freighters attached to fleets extend the range of that fleet by increasing total fuel capacity. Troops, Fuel, material, and aircraft are critical to base defense. Bases will not take direct orders but will use Fighters and Bombers for defense and attack if they are available.