[ryanglavin]

Originally Posted by Grey pilgrim

Well,
Let me say that theoretically the largest was XXI type. Both in lenght and overall appearance.
The problem is that practically, XXI type, was not used in the war at all except probably one copy or prototype.
So the biggest ones were the most advanced IX type U-boats in my opinion.
The smallest ones were coastal IID type U-boats.

Your confusing me...
IXD2

Displacement:
(tons) 1616 (sf)
1804 (sm)
2150 (total)
Length: (m) 87,60 oa
68,50 ph

XXI


Displacement:
(tons) 1621 (sf)
1819 (sm)
2100 (total)
Length: (m) 76,70 oa
60,50 ph

The XXI is both smaller and lighter...


(Info from Uboat.net)