f imaginative warfare.

The "Junon" business was a casual episode. Warren was already
preparing for his attack on Craney Island. This little strip of
ground, a half-mile long by two hundred yards across, lies within easy
gunshot to the west of the Elizabeth River, a narrow channel-way,
three hundred yards from edge to edge, which from Hampton Roads leads
due south, through extensive flats, to Norfolk and Portsmouth. The
navy yard is four miles above the island, on the west side of the
river, the banks of which there have risen above the water. Up to and
beyond Craney Island the river-bed proper, though fairly clear, is
submerged and hidden amid the surrounding expanse of shoal water. Good
pilotage, therefore, is necessary, and incidental thereto the
reduction beforehand of an enemy's positions commanding the approach.
Of these Craney Island was the first. From it the flats which
constitute the under-water banks of the Elizabeth extend north towards
Hampton Roads, for a distance of two miles, and are not traversable by
vessels powerful enough to act against batteries. For nearly half a
mile the depth is less than four feet, while the sand immediately
round the island was bare when the tide was out.[163] Attack here was
possible only by boats armed with light cannon and carrying troops. On
the west the island was separated from the mainland by a narrow strip
of water, fordable by infantry at low tide. It was therefore
determined to make a double assault,--one on the north, by fifteen
boats, carrying, besides their crews, five hundred soldiers; the other
on the west, by a division eight hundred strong,[164] to be landed
four miles away, at the mouth of the Nansemond River. The garrison of
the island numbered five hundred and eighty, and one hundred and fifty
seamen were landed from the "Constellation" to man one of the
principal batteries.

The British plan labored under the difficulty that opposite conditions
of tide were desirable for the two parties which were to act in
concert. The front attack demanded high water, in order that under the
impulse of the oars the boats might get as near as possible before
they took the ground, whence the advance to the assault must be by
wading. The flanking movement required low water, to facilitate
passing the ford. Between the two, the hour was fixed for an ebbing
tide, probably to allow for delays, and to assure the arrival of the
infantry so as to profit by the least depth. At 11