Dear John,

I can't help re "Regenbogen" (sorry) - I have not researched that aspect in any detail.

However, in view of the follow-up comment which mentions the Walter boats, if you wish to pursue that, then you might like to look at the list of "articles" on uboat.net, where you will find one dated 12 Oct 2010 which describes what happened to U-1406 and U-1407 in Cuxhaven.

Hope this helps, and good luck with your original query.

Yours aye

Derek