Our first so-called "chicken bus" from the historical town centre to the marina was full of kids playing loud music on their way to school. So, although we have started our journey at a tourist resort, it wasn't long before we felt we were experiencing the real Mexico.

From the marina, it was a two hour return trip over rough sea to the Marietas Islands. This is where La Playa Escondida (Hidden Beach) can be found, after swimming 200m through a tunnel. We picked a bad day to do this, as the swell was lifting our heads very close to the rock ceiling above. It was quite a challenge to get through to the other side, but even more of a challenge for the small children and non-swimmers. We found it quite unbelievable that these groups were allowed to do it. They were given little more help than a life jacket and a towrope.

We also did some snorkelling amongst the fish, but it was difficult to enjoy the experience because of the large number of people in the water.

On our second day, we took a water taxi to the remote cove and community at Yelapa and strolled up to one of the two waterfalls there. Plenty of birdlife here, but one of the reasons we chose to do boat rides was in the hope that we might see whales. No such luck, as they are late arriving into the bay this year because of hot weather. I don't know what excuse the other creatures had, but also absent were the dolphins, turtles, stingrays and blue-footed boobies.

The food has been excellent so far, including seafood varieties of Mexican favourites such as crab tacos and shrimp enchiladas. It was a good place to start our trans-Mexico bus journey. Tomorrow we leave the Pacific Ocean behind and begin our long journey to the Atlantic Coast on the opposite side of the country.

Note - check out the video section for the tunnel swim (if I ever manage to upload it), and you'll see why I didn't take the SLR camera to the hidden beach!