The key to hunting a trophy Hippo is to be patient. While some old bulls can get a little crany and defensive, 90% of Hippos are shot while they are in the water from about 50 yards away/
Shot placement is key and you should make sure with your PH where to shoot. A brain shot in most cases is desirable, but the hunter always needs to be ready to follow up. He is also backed up by his PH on second and third shots if needed.
The hippo, once shot in the water will sink and then will float within a couple of hours. The goal is to harvest the hippo as close to the shoreline as possible, and in shallow water, from where you can see it and keep an eye on it. Stay away from hunting hippo in a strong flowing river as you might loose your trophy. Once the hippo starts floating, the retrieving part of the hunt starts. It is interesting and sometimes quite dangerous.
Watch your PH or one of the trackers wade and swim into crocodile and hippo invested waters to tie a rope around the hippo. (Sometimes in deeper waters, a small boat is used).
The hippo will then be dragged onto shore with the help of a safari vehicle or through manpower provided by local villagers.
Most of the times, only the scull with tusks and the hippo skin is retrieved, and the meat gets used for feeding the villagers, or in some cases for Lion Bait (In the latter case the decision is made out of necessity and not choice.