chickenfeet

As i was returning from port Credit on Sunday I saw the Hippo Bus in the water. I've seen it on city streets often enough but never in the water. I've always supposed the Hippo Bus to be a tarted up DUKW but I must be wrong because the DUKW is definitely a 6 wheel drive vehicle and the Hippo Bus has only 4. Anybody got any ideas on what it is based on?