When to send another eel in?

[Walruss]

Ok, first an excert from my log


0300- made contact with lone merchant north of shetland islands, est. GRT 4900. Submerged to make attack as sea is too rough for deck gun. Visabilty to 4,000 meters, foggy.

0404 Two torpedoes launched at short range, one hit observed well aft of boat. Second torpedo assumed to have missed, speedmis-estimated.

0420 ship not slowing appreciably, slight list. decided to attack again with stern torpedo

0510 Stern tube fired at short range, impact observed dead amidships. Ship immediatly slowed to ~ 2 knots or thereabouts. Dropped back to 1500 meters astern of target to observe


0815 : ship still making headway at 2 knots, afire and listing but not seeming to sink at any apreciably fast. Decision to attack again.

0845: Fired 4th torpedo at target from fore tubes, hit observed just aft of funnel. Ship immediately slows to 0 knots, lists heavily submerging her port side. Crew abandon ship.


My question is this: Would you have done that differently? I screwed up my speed estimate on the initial attack, elsewise I'd have had a lovelly setup of one eel below the funnel and 1 eel halfway between the funnel and her stern. I find this the best way to at least totally disable the ship, and normally sinks ships up to about 7,000 grt. I was in a bit of a hurry because that close to the shetlands, with daylight just breaking, i figured that aircraft, or maybe a destroyer, would soon be on their way to help the strickened ship. However 4 torpedoes for a paltry 5000 GRT does make me feel a little... sad. I've not even made it to my patrol zone and I'm down to 7 torpedoes all up (it's been a good trip out though- I've racked up 20,000 GRT in 6 using those torps). The bugger of it is, if the weather were any better I'd have just surfaced and put a few holes in her hull with the much cheaper.

How long do you wait before you put another torpedo in a wounded ship? if it's a lone merchant do you even stick around, or just continue on your merry way?

Walruss