Ghost Ship?

[Seaman Staines]

Cruising north of Scapa Flow (AM34) on my way to my assigned patrol, I picked up a nearby contact and plotted my intercept course. Soon enough, a large merchant comes into range and promptly slips beneath the waves with a torpedo in her bow. I chalk up a convenient kill and resume course for my destination...

Moments later, I get another contact on top of the merchant I just sank (now behind me). It's close enough to warrant investigation, so I check the rearview mirror and there's another large merchant there. So I sneak up and sink it. More tonnage. Gotta love it.

I do a quick scan with the hydrophone. Nothing out there, so back to my original course when suddenly...another contact right on top of the previous two. Check the rearview mirror again. Another large merchant?! I left it alone this time, but it seems to me I could have expended all my torpedoes just sitting there waiting for the ship to rise from its watery grave.

Anyone seen this before?