[Bull Snipe]

May be wrong about the extra boats on Powhatan. But the plan never called for the supply ship or the warships to enter Charleston Harbor. They were to be anchored about 4 miles from Sumter. That would have put the ships beyond the range of the Confederate gun batteries. The tugs and small boat would come within about 1200 yards of those batteries and have been well within their range.

[DiogenesLamp]

May be wrong about the extra boats on Powhatan. But the plan never called for the supply ship or the warships to enter Charleston Harbor. They were to be anchored about 4 miles from Sumter. That would have put the ships beyond the range of the Confederate gun batteries.

So how were they going to use "all the force" at their disposal to place both men and supplies into the fort?

Warships aren't much good if you don't actually use them.