Fishermen are calling on the Royal Navy for help after dummy mines have damaged their boats and nets.
Recently, six of the metre-wide, heavy metal mines have been caught off Looe in Cornwall.
Fisherman Ivan Toms said the mines are resulting in lost fishing time and are "polluting the sea".
The Royal Navy says warnings were issued when the mines were placed on the seabed and it will review the compensation claims.
Mr Toms said he lost a "whole day fishing" when he and his son came across two mines on Friday night.
His son cut the mines free from the trawl and narrowly missed being crushed as it crashed on to the deck, he told the BBC.
"It's not just us, the other boats are catching them."
Mr Toms said fishermen have hauled up six mines in the last few weeks.
Despite being inert and not containing any explosives, the mines can cause damage to the boats at sea.
Mr Toms wants compensation for the damage to his boat and fishing gear and for the Royal Navy to use another area for training, away from winter fishing grounds.
There is a telephone number on the mines for finders to ring and Mr Toms says he has called it several times.
A Royal Navy spokesperson said: "A number of dummy mines containing no explosives were laid for a recent trial, and mariners were informed via local notices and warnings."