A surrendered and beached German submarine, probably at Portsmouth RMG PW2211

A surrendered and beached German submarine, probably at Portsmouth
Although not so down by the stern, this appears to be the same surrendered German submarine as shown in PAF1866 and PAF2084. If so it is on mudflats in Portsmouth Harbour and is identified by Wyllie's inscription on the latter as 'U131'. However, that cannot be the case for reasons explained in relation to those drawings and what it might alternatively be is not clear for technical reasons, especially since no record has yet been found of such a boat being beached at Portsmouth prior to breaking up. This is a puzzle yet to be resolved as regards all three drawings.