Question about WWII German U-boat bow planes

Originally Posted by Gannet

One thing I did notice is the German WWII submarines had their bow planes always submerged even when the sub was surfaced; whereas, the US and British submarines bow planes were either at the waterline or above the waterline when not retracted.

As mentioned already, the fixed fin had to produce lift when surfaced.
As far as I know the British and US boats had not such a sharp bow (less buoyancy), as the German boats.
Apart from that, I think the fin below WL was the better idea anyway, due to the much faster reaction when diving.

[wardd]

us subs had to range the pacific and the added drag of the planes would have cost fuel

Originally Posted by wardd

us subs had to range the pacific and the added drag of the planes would have cost fuel

That should be valid for the German boats and the Atlantic too. But diving fast was the more important feature than some 0,2 kn better speed.