What diseases were there in the trench in World War 1? Trenche foot was very common in the trench warfare. caused from wet feet and not being able to change their socks and boots. Edit
Repels Sharks No.........human urine actually repells sharks and other fish.
A few things that could attract a shark to a human is blood (which can also cause a feeding frenzy) and a human paddling out to catch some waves (surfing) looks like a seal so that can also attract sharks, however sharks have a keen sense of smell so it is more likely that blood will attract sharks.