With pirates prowling and preying along the Africa coast Kenya’s Maritime Authority has set up a maritime security zone for vessels waiting to enter the port of Mombasa.
You might be a little careful where you drop your hook, though. There is a now-disused explosives dump right in the middle of the zone and another immediately outside the zone to the north as you can see in this hand-annotated chartlet by the KPA.
Elsewhere, dumped munitions are considered a problem even though some of them were discarded as a long ago as post-world war 1 around the European coast. As recently as 2005, three fishermen were killed in the southern North Sea when a Second World War bomb exploded on their fishing vessel after having been caught in their nets.
For those who like to worry, check out the OSPAR assessment on dumped munitions here.