Twice a year the migratory herds in the Mara-Serengeti region migrate in search of fertile grazing. That involves a treacherous crossing of the Mara river. Going north in the spring and south in the autumn. We were very fortunate to witness a crossing on our only visit to the Mara in 2004. Many seasoned photographers have never seen one. The crossing is perilous and the herds gather for days before summoning up the courage to make the crossing. Once the first wildebeest goes it is bedlam with beasts leaping into the water in a frenzy. Hazards are many, broken limbs are common and fatal. Nile crocodile await and can easily drown a full grown wildebeest. We were pleased to see the whole herd cross without incident. Photographically this was a challenge, in part because of the limitations of the 2004 era digital cameras and in part because the scene was just so exciting to witness that it was difficult to concentrate on getting great images.