I am just saying that the wooden ships of the era were not C-130 of todays Airforce. They couldn't just fly by and drop pallets out by parachute or slide their palletize loads on the runways without stopping. If you will notice in picture in the link below that is what I saw of Fort Sumter from Fort Moultrie. This is not a closeup or enlarged picture but simply a view across the shipping channel from Moultrie to Sumter. It also shows why Fort Sumter so effectively blocked the Harbor entrance.

For the heavy batteries of Moultrie this would be like shooting fish in barrel if a ship was tied up to the docks for longer that 15 minutes. They could almost site their guns right down the barrel. IF you intended to seriously resupply and/or reenforce fort Sumter from the sea after January 1861, it would require that these guns of Moultrie and the guns of Johnson island be silenced. Pickney Island was another matter but could still do the same but less effectivelyThe only way to do that would have to be a land assualt.

That is why the proposed resupply of Fort Sumter in April 1861 was not in my opinion a serious attempt. Or else Ole Abe and Scott thought that their ships would be allowed to sail into Fort Sumter unchallenged.