I took the photo at the top of this page on a recent trip to Botswana, (and yes, it was with an iPhone!). To reach that location, we had to take a 45-minute ride in a four-seat plane from Maun, a 15-minute ride in a Land Rover, followed by one-hour ride on a boat through all manner of tall grass and swamp.
On our way out of the camp, we encountered a pair of hippos. Here, I must admit my own ignorance. I have always regarded hippos as "cute," perhaps because I grew up playing the board game "Hungry Hippos." As I took photos of the massive creatures, their tiny ears peering above the surface of the water, one of them swam in front our boat, submerging itself with a great splash. The driver of our boat, a man by the name of Carlos, who grew up on the Okavango Delta, gunned the boat forward, as we were in a narrow channel. As we lunged forward, passing over the hippo, we felt a huge jolt. I was aghast. I thought we had killed the hippo, or caused it grave injury. Carlos later explained the hippo was probably fine, (I have no idea if he was just trying to placate my fears).
What I have since learned, is that Carlos may have very well performed an act of heroism. It turns out that hippos pose the greatest threat to humans than any other animal in the African wilderness. They are grass eaters, so they aren't out for human flesh, but they are very territorial. After some very non-scientific research with involved about 20 minutes of googling, I came across a figure I found hard to believe: hippos account for 3,000 human deaths in Africa each year. Setting aside whether that figure is accurate, I did come across a verified report from 2014 in which a pair of hippos had overturned a boat, killing 13 people, mostly African children who were on their way to school. Check it out: