Yup, either Uboat.net or those guys are getting quite a few facts wrong:
The picture resembles Port Nicholson?! The picture in that article is exactly the same as on the page of
Port Nicholson in uboat.net. The ship was hit and sunk by U-87 during it's third patrol.
Also U-87's track for its
3rd patrol, 19 May - 7 July 1942, shows it operating in Northern Atlantic all the time. Daily positions for all 51 days of the patrol, so either Philadelphia experiments were actually a Nazi affair or the treasure guys are wrong.