The grey whale was once known as the 'devil fish', because mothers were known to attack the whalers' boats in defence of their calves. Now these gentle giants are renown instead for their friendliness and curiosity.
From December to April, small wooden fishing boats called pangas - just half the size of an adult grey whale - take tourists out on the lagoons.
The animals approach the boats and appear to seek human contact.
These are some photos from a short trip to Laguna Ojo de Liebre - the most northerly of the breeding lagoons - in January 2004.
To reach the lagoon we made a long journey by road which took us through some extremely arid landscape. The cacti along the route were amazing in terms of both their size and shape.
At the lagoon, the baby grey whales are around 4.5 metres (14.5 feet) long at birth, but this one (just visible on the left of the first picture below) looked tiny next to its mother who was probably about 14 metres (46 feet) long.
As well as close encounters with mothers and their babies, there was lots of other activity to observe, including breaching, flipper-slapping (right) and spyhopping, fluking and mating (below).
The mating groups typically comprise one female and two to five males. This one involved three whales and was fairly chaotic!
The bones of a whale that had been washed up dead on the shore of a lagoon had been reconstructed into a full skeleton. This gave visitors a rare chance to 'see inside' a whale and appreciate the similarities and differences between cetacean skeletons and our own. The upper part of a grey whale skull had also been washed up on another shore.
Baja's lagoons are home to the usual compliment of fish-eating birds, including brown pelicans and ospreys. Nesting platforms had been built for the ospreys, which they seemed to have taken to.