Eighteen ships of equal size were moored by the bank six deep.

Great planks were laid across them, and a sloping platform having been formed, the towers were by the efforts of thousands of men moved up and placed on the ships.
"If we do not destroy those towers, Egbert," Edmund said one day as he saw them slowly moving into their position on board the ships, "all is lost, for from their summits the Northmen with their bows and javelins will be able to clear the walls, while those below effect a breach at their leisure." "That is true enough, Edmund, but I do not see any way to destroy them.
Unfortunately we have no boats, or we might fill some of them with combustibles, and tow them down until near enough for the stream to carry them upon those vessels; but even then the chance were small indeed, for the Danes would swarm out in their boats and manage to tow or push them so that they would not touch the ships." "I should think, Egbert, that if we could get some skins or planks we and our band might, when it is quite dark, sally out and take to the water at the lower end of the island and float down quietly for a mile or two, and then gain the further bank; then we might march along quietly until we reach those ships.

The Danes know that we have no boats, and will not fear an attack.

We must not do it until an hour or two before morning, when, after spending the early hours of the night as usual in feasting and drinking, they will sleep heavily.

Just before we are ready to begin a small party can unmoor two or three of the boats by the bank and push them out, one to the outside of each tier of six vessels, so that we may have a means of retreat across the river.
When that is done we will make a rush on board the ships, cut down any Danes we may find there, and set fire to all the vessels.