We've sprung a leak!

It wouldn't be a Star cruise without a breakdown. This time we're leaking. Fortunately it's not a leak from outside - that would be a problem - but a leak from the engine cooling system.
I spotted it the night before last as we were due to head toward the Montgomery Canal - the coolant header tank was empty. But it was dark, it was raining and we were moored outside the pub. I decided that after a pint and some dinner things might seem less fraught. And they did: it was either overheating for some unknown cause - possible but probably fixable; a leaking pipe - fixable; or a blown head gasket - not so fixable but least likely since the engine was running fine.
I decided to sleep on it.
The next morning what was revealed was a copper pipe from the engine to the skin cooler which had chafed through and was drip dripping away. Snag was that in all my spares copper pipes and brass fittings were conspicuous by their absence. So we decided to potter on down the Montgomery, checking the coolant and topping up as needed and fix it when we got to the other end.
This morning I got a bus into nearby Oswestry (free, courtesy of my old codger pass) picked up some bits, headed back and spent the afternoon sorting it out. Now we're up and running and leak free.