Sorry Mike but I don't think we are talking about the same thing.
I've never been to Ireland but living in a place with scads if Irishmen, a few of whom are Pioneers, and having dated a red-headed girl from Akill Island, who wasn't but should have been, I know what a curragh is and I don't think that is what our requester had in mind. Light or not curraghs are high-sided deep water boats that must have a fairly substancial framework because they don't have an inegral deck to help soak up exterior forces.
I assumed the query was about a rowboat that could boogie like a kayak. Long, light and shallow. A kind of topless SOF kayak proplelled by sculls. If that is what the requester is after I think it is an idea that will be difficult to pull off. The leverage of several oars lustily applied to the gunnals of a boat frame that is too light to stand up to the forces will make the frame flex and break, eventually.
If the program was for a craft to be paddled for pleasure in protected waters, no problem. But two guys pulling on oars for all their worth changes everything.

: Hi Charlie,
: If Alan, the original poster, was to go the way of a SOF open boat, a design
: similar to a currach in construction technique would not flex under oar
: pressure. The currach uses a double gunwale, one above the other, 6 to 9
: inches apart, with stanchions between the gunwales, 12 to 18 inches apart.
: These are nailed in place. The ribs fit into the lower gunwale only and
: are almost semi-circular in bend. There's more stringers than even Alaskan
: kayaks have but not as many as a birchbark canoe. There's no keel as
: such, just another stringer the same as the rest.
: A currach built for two men to row is light enough for the two men to carry
: easily.
: They're fast but don't have as much inertia as a wooden hull the same size.
: Good for acceleration but they don't have too much glide.

: Being designed/evolved for the Atlantic sea off Ireland, they'd handle the
: river waves mentioned fine.

: Mike Savage
: South West Cork