Now it was obviously one of the duties of our Tenth Cruiser Squadron, entrusted with the interception of shipping in the north, to see that Germany did not receive this ore. But having regard to the delicacy of not violating the waters of a neutral nation, and bearing in mind the pilotage difficulties off a coast studded with islands and half-tide rocks, this was no easy matter. It was here that the small ships came in so useful. We can go back to June, 1915, and find the armed trawler _Tenby Castle_ (Lieutenant J. T. Randell, R.N.R.) attached nominally to the Tenth Cruiser Squadron, but sent to work single-handed, as it were, off the Norwegian coast intercepting shipping. As a distinguished admiral remarked, here she lay in a very gallant manner for twenty days, during which time she sank one enemy ship, very nearly secured a second, and was able to hand over to the Tenth Cruiser Squadron a neutral ship with iron ore. It was a most difficult situation to handle, for it required not merely a quick decision and bold initiative, but very accurate cross bearings had to be made, as these offending steamers were on the border-line of territorial waters. That great enemy of all seamen irrespective of nationality, fog, was in this case actually to be a very real friend to our trawler; for in thick weather and the vicinity of a rock-bound coast full of hidden dangers, skippers of the ore ships would naturally be inclined to play for safety and stand so far out from the shore as to be in non-territorial waters. A further consideration was that owing to the effect of the magnetic ore on their compasses they could not afford to take undue navigational risks in thick weather. What they preferred was nice clear weather, so that they could hug the land.