I have reliable information that the Rebels have two Torpedo Boats ready for service, which may be expected on the first night when the water is suitable for their movement. One of these is the David which attacked the Ironsides in October, the other is similar to it.
There is also one of another kind, which is nearly submerged, and can be entirely so; it is intended to go under the bottoms of vessels and there operate.
This is believed by my informant to be sure of well working, though from bad management it has hitherto met with accidents, and was lying off Mount Pleasant two nights since.
There being every reason to expect a visit from some or all of these Torpedoes, the greatest vigilance will be needed to guard against them.
The Iron Clads must have their fenders rigged out, and their own boats in motion about them.
A netting must also be dropped overboard from the ends of the fenders, kept down with shot, and extending along the whole length of the sides; Howitzers loaded with Canister on the decks and a Calcium for each Monitor.
The Tugs and Picket Boats must be incessantly upon the look out when the water is not rough, whether the weather be clear or rainy.
I observe the Iron Clads are not anchored so as to be entirely clear of each other's fire if opened suddenly in the dark. This must be corrected, and Captain Rowan will assign the Monitors suitable positions for this purpose, particularly with reference to his own vessel.
It is also advisable not to anchor in the deepest part of the channel; for by not leaving much space between the bottom of the vessel and the bottom of the channel, it will be impossible for the diving Torpedo to operate except on the sides, and there will be less difficulty in raising a vessel if sunk.
Rear Admiral, Commanding
South Atlantic Blockading Squadron.