Overnight we cruised in far more calm conditions to the largest of the Galapagos islands, Isabela. Despite it being somewhat overcast, the ever optimistic Darwin suggested we stick with the plan for the morning, which was to hike to the rim of the 10km wide caldera of Sierra Negra volcano. The ever optimistic group agreed.

A bone shaking bus journey later we were ready, rain coats and wellies donned, chilly mist present and correct. However, half an hour of walking later we were under an enormous blue sky and scorching sun. A tad uncomfortable. However, layers shed, we reached the rim.

The view is incredible, a 10km diameter caldera of moon-like lava flows. The last eruption was in 2005 and so there is essentially no vegetation at all in the crater.

A swift visit to a favourite haunt of flamingos added one whole flamingo to our tally, taking it to 4. We decided we were going to start marking them like sheep to make sure we weren't being diddled.

We also popped into another tortoise breeding centre before getting back on board the Beluga to set sail up the coast.

It now being a scorching hot day we convinced the crew to allow us a short swim before heading off. Fabrice decided it would be a good plan to jump off the top deck whilst wearing his snorkelling goggles. Needless to say they have not been seen since.

Darwin mentioned that there may be an opportunity to see some whales on the cruise up the coast to the next day's location. How unexpectedly right he was. We saw around twenty Minke and Bryde's whales all around the boat for about an hour or so, two coming so close that they passed right underneath the boat. This was unprecedented even for the crew, who were up on deck with us taking photos. Not sure who was steering the boat.

The south western coastal landscape of Isabela is also worthy of mention, a desolate lunar desert of little satellite volcanos like nothing we had seen before.

And so ended another amazing day.