I've seen the programme on this trip. (Did a whole thread on BM which JF threw out with the big spring clean)...
They had to sew the leather boat in icy waters (under the waterline, from the outside)
And they met up with an Icelandic craft and celebrated with Black Death!!!!!
(now you do realise I'm talking bout the Tim Severin trip not the St. Brendan one cos the Irish camera crew went on strike on poor oul St Bren.)