Didn't U-47 run aground on her approach to Scapa at one point? :hmmm:

Somebody should've told this man about a year ago!

http://img11.imageshack.us/img11/535/acolesastute.jpg

There is little information regarding U-Boats in 1914-18 that operated in Scapa or its approaches without being lost so it's likely there was not much hydrographic data in the KM records for that area.

My only point was that it is probable that the there was relatively solid navigation information on much of British coastal waters due to Germany's Great War experience where many of the U-Boat attacks took place in the shallows of the Channel, Western Approaches, North Sea and Irish Sea.

As I recall, U-47 touched bottom on a raising tide while trying to circumvent a series of block ships while on the surface. Not quite the same navigation problem as stalking shallow water coastal sea lanes submerged.

That particular area between the two sunken block boats was only usable during high tide. On the same date (oct 14/39) I took my boat through the same passage; if it weren't for a storm raging on it would have been difficult to make it through. One spot that (on the map) was supposed to be water was shallower than the map and did run aground once. Luckily it wasn't too harsh and was able to back out of it and get back on course.

Even so still had to make a '3 point turn' to get between the two subs safely. It's a tribute to Prien's navigational skills and previous experience that he made it through unharmed and unnoticed. Though it was a major help that he was able to use both engines - one going forward and one in reverse to force the boat into making very sharp turns like what was needed at that location.

I use my fathometer all the time and tonight it saved me in shallow water where I was able to stay 10 meters off the harbor sediment and next to a disabled British warship I hit with an eel ... the 4 others that hunted me would not drop charges close to their stricken vessel .. so in time (6hrs) they gave up. I had conning tower damage so I navigated her by chart map and using my fathometer readings I manuevered closer deep into the cove and shallower where I knew they could not come after me. I stayed submerged until nightfall. Assured the British vessels were gone, I surfaced, repaired all damage and took off for base on the surface full ahead and pass the coffee.


:salute: