It has been suggested that "blocking the exit" was not the best method of preventing the egress of German vessels from the Zeebrugge canal. An alternative method, that of destroying the lock-gate by gun-fire, was referred to. The idea sounds plausible enough at first. As a matter of fact, many attempts had been made, by means of long-range bombardments, to achieve that end. They had all failed. The lock-gate appeared to have a charmed life. Huge shell had burst in its vicinity and yet it still remained intact. The suggestion was then put forward that the lock-gate should be bombarded _from close range_ under cover of smoke or gas. This suggestion was accompanied by the opinion that an attempt at blocking the channel would be futile. I am much puzzled at this idea of close bombardment. For it was as obvious, as it was known to be a fact, that the Germans would withdraw the gate into its armoured recess immediately a bombardment was suspected. This would have been the work of a few moments; the outer lock-gate would have been rendered absolutely immune from destruction. The argument that there were two lock-gates, outer and inner, and that the Germans could not withdraw both, owing to the fear of the canal running dry, also sounds plausible until it is closely examined. Firstly, however, it is clear that the canal would only run dry if both lock-gates were opened _at low tide_; secondly, an {44} inshore operation at low tide would preclude the use of any craft other than those of shallow draught; thirdly, owing to the presence of the outer wall of the Mole, whose height would be over forty feet at low tide, the bombarding vessels could only obtain a direct line of fire at the lock from a position inside the Mole where the extensive shoals would allow very little room for manoeuvring, to say nothing of the defences on the Mole itself; fourthly, the canal, even if emptied, would refill from the rising tide within a few hours, and there was no certainty that the temporary evacuation of the water would cause serious damage; and lastly, one may assume, if there was really any substance in the idea, that the Vice-Admiral whose many long-range bombardments had failed to achieve their purpose would have long since attempted a short-range attack. So, the decision to block the entrance at Zeebrugge having been reached, the best position for blocking had to be considered. It has already been shown that the narrowest portion of the channel to seaward of the lock was situated near the shore ends of the wooden piers. Another position even narrower in size was that of the lock-gateway itself. But the mere width of the position chosen was by no means the only consideration.