To the 16 gunboats he had in the Cape Fear River, Porter issued an operation plan for an attack on Fort Anderson that was to coincide with the naval bombardment of General Hoke's flanks and the launching of General Schofield's turning movement on the east side of the river. (General Hoke was on the east side of the river as well.)
The gunboats were instructed to approach Fort Anderson bows-on to minimize the target presented to Southern gunners (who had the ranges down for the channel), while the monitor USS Montauk would lay down a covering fire from close in.
When the fort's fire slackened, the gunboats would approach and drive the gunners from their positions with grapeshot and canister. With the enemy's battery this silenced, the fleet would shift to carefully aimed point fire to dismount the guns.
Goodbye Fort Anderson. --Old B-Runner