They will spot a periscope, under normal conditions, at a pretty good distance; which does not mean that that periscope is at once going to be blown out of the water. Hitting a piece of 4-inch pipe at any distance is not easy; the pipe moving and the ship moving does not make it any easier.
But the submarine has shown herself. To get her torpedo home she will have to move nearer. With a thousand eyes looking for her and five, six, a dozen ships with four guns or more apiece waiting to have a crack at her, she is not going to have a pleasant time after she moves nearer. She must show her periscope again to locate her target. To show her periscope she must get her hull somewhere near the surface; it takes a little time—not so much, but a little time to get her hull safely below again; and while she is doing that who can say that not one of our five, six, or a dozen ships will be handy to the spot? And if one of our ships should happen to be handy enough, what can save the submarine from being rammed? And if she is rammed there is no hope for her—she is gone.
I am pretty much of one mind with our first officer in this submarine matter. In the middle of the combat off the French coast he was making the rounds, cutting away the lashings which held the life-boats to the davits—this in case we had to leave the ship. He had a squint at the banging guns, the charging troop-ships, the flying destroyers; and then he looked up long enough to say: "A fat chance a U-boat would have if she so much as stuck her nose out. In four seconds she'd be like a rabbit among a pack of hunting-dogs. She might get away, but I bet you no bookmaker would take her end of it."
This argument does not apply to a slow-steaming freighter going it alone; it is for the matter of troop-ships moving at a fairly good speed. For myself that time the fleet steamed in direct column ahead, one ship jam up behind another, in a rough sea and on a black night, at high speed without lights of any kind, they did a more difficult thing than to evade or stand off half a dozen U-boat attacks. No fleet of ships can be put beyond all danger of submarine attack, but the danger to the subs can be made so great that it won't be worth the price the attacking force will pay.
I do not know how many U-boats were in that attack. The official figures will no doubt be given out in time. Our moderate estimators here put it down as three, with one transport ramming and sinking one U-boat. Two honest lads of one of our own forward gun crews say that our ship bumped over another. They felt the bump. Perhaps they did, but bluejackets at twenty years of age are apt to be optimistic, as witness:
The day after that U-boat fight the skipper, first officer, chief engineer, and myself were trying our French on a waiter in a café ashore, but not quite putting it over; we had to resort to a little English to get action for one important item of our meal. A party of American bluejackets—gun crews—were at another table. They heard us speak English, whereat one of them called over: "Say, you guys comprong English? Wee, wee? Then you oughter been where we were yesterday. Yuh'd seen something. Fighting U-boats we were. Comprong? U-boats—wee, wee, U-boats. Thirty-six of 'em came after us an' we sunk twelve. Whaddyer know about that?" We did not know, so we opened up a bottle of the ordinary red wine of the country, price deux francs, and drank to their enthusiastic health.