We left early to go Halong bay to see the limestone karsts in the bay. We had booked a tour as this is the only practical way to see the bay. We were in a group of 15 with Swiss trainee doctors, 4 rugby players from France and a mixture of Brits, Italians and Aussies. It took about 4 hours to get down to the port - including the tour of hotels to pick up people and the obligatory stop at a tourist shop. The trip was only notable for an entry of 'most unusual things on the back of a moped' - this entry was a dead cow! The port was chaos as most of the boats go out at the same time. We were shepherded to the boat and were off. The weather was a bit cloudy but that soon started to break up as we left the port. After a seafood lunch on the boat, we stopped at a set of caves. It's only claim to fame seems to be a strange and slightly rude stalactite. After that we moved off and had a chance to explore some other sea caves using kayaks. I was with Fran who gave a lot of advice about direction but didn't provide too much propulsion. Still it was enjoyable and took us to places that weren't accessible otherwise. We weren't the worst at kayaking despite being the oldest - that honour fell to the Italians. After that it was time for a quick swim with the French demonstrating synchronised diving from the top of the boat.We had a restless night on board - the boat was very noisy with the generator and all the creaks and groans. It was up for a 7:30 breakfast (I hate tours!) before the boat moved on. We were supposed to do some more swimming but nobody was that keen as it was a bit breezy. Instead we spent a very pleasant morning laying on the top of the boat watching the amazing scenery go by. After lunch, we were back at the port and the trip back to Hanoi. We were on the night train down South, so we had a couple of hours to sort ourselves out in Hanoi before getting the train.