So much for the Mole itself. Across the channel the Germans had placed booms. One of these, consisting of four Rhine barges, was moored between the eastern end of the broad part of the Mole and a buoy situated two hundred and seventy yards to the southward. These barges were filled with stone, had nets slung beneath them, and were connected together by wire hawsers. If a surface vessel attempted to pass between the buoy and the Mole she would be brought up by this boom and probably damaged by collision with one of the barges. If a submarine attempted to dive underneath the barges she would be caught up in the nets. The other boom consisted of entanglement nets moored between a series of buoys to the southeastward of the barges. Any ship attempting {33} to pass through them would probably have her propellers entangled, with the result that her engines would be brought to a complete stop. Thus, whichever boom was encountered by a ship, the latter would, at the least, be partially disabled and stopped. The Mole batteries could then have sunk her at their leisure by gunfire. The only route by which a vessel could pass clear of these two booms was that between the southeastern barge and the northern entanglement net; i.e., within two hundred and fifty yards of the heavy gun battery on the Mole. But even if, by dint of good fortune or special good management, a vessel managed to pass the Mole batteries and the booms, she would still have to run the gantlet of the naval vessels in the anchorage and the batteries on shore before reaching the canal. [Illustration: THE NORTHEASTERN END OF THE MOLE a. The shadows of the parapet wall and of the lighthouse at its extremity b. The Mole batteries c. Trench system surrounded by barbed wire d. German torpedo craft alongside Mole e. The barge boom f. The boom of entanglement nets] The German torpedo craft, which were available for local duty, used to berth alongside the inner side of the Mole, close to the westward of the barge boom. By virtue of their guns, torpedoes, and searchlights, and the fact that they probably kept up steam in readiness for instant action, these craft provided a valuable addition to the Mole and canal defences. The foregoing description of the local defences at Zeebrugge has probably been sufficiently detailed to lead to the conclusion that the Germans were fully alive to the possibility of attacks on the Mole or canal. Whether or not they considered that such attacks would only form part of some more ambitious operation, such as a military landing on the coast, our enemies had left practically no stone unturned to repel them. The defence measures must have {34} appeared, especially to those on the spot, to be more than sufficient.