Unlike Somali pirates, who have used the single technique of seizing ships and their crew for ransom, there are three types of piracy in the Gulf of Guinea.
According to a former member of the British Special Forces, Sven Hanson, who now works for a private maritime security company in West Africa: "You've got the classic armed robbery at sea, which has been happening for centuries, where pirates board a vessel to steal money, radios and mobile phones.
Unlike Somali pirates, who have used the single technique of seizing ships and their crew for ransom, there are three types of piracy in the Gulf of Guinea.
According to a former member of the British Special Forces, Sven Hanson, who now works for a private maritime security company in West Africa: "You've got the classic armed robbery at sea, which has been happening for centuries, where pirates board a vessel to steal money, radios and mobile phones.
"The next scale up is cargo theft, the predominant threat in West Africa, when pirates hijack an oil tanker, take her to a quiet place, bring another ship alongside and siphon off the oil.
"Third, there's kidnap for ransom when pirates seize the expatriates."
In most cases of West African piracy, the pirates want the cargo, not the crew.
This means levels of violence are higher than they are off the coast of Somalia, where the pirates need to keep the crew alive in order to obtain ransoms.
"The attacks are deadly and brutal," says the first female head of the Nigerian trawler owners' association, Margaret Onyema-Orakwusi.
"The pirates throw the captain and chief engineer into the cold room where we store the fish. They freeze to death," she says.
"Piracy has decimated the fishing industry; 100,000 jobs have been lost and Nigeria now imports more than 80% of its fish."
Rear Admiral Samuel Alade Rear Admiral Samuel Alade believes the government's pirate-hunting agencies are having an effect
A pirate based in the Niger Delta said the only way to get a share of the region's oil wealth was to rob ships.
"We attack seafarers and we beat them so they'll tell the government," he told the BBC.
"They're eating the oil companies' money while we go hungry. We have to collect their money in order to survive."
In its efforts to combat maritime crime, Nigeria has a bewildering number of government agencies, partnerships with private security companies, even deals with former seafaring militants who have themselves carried out spectacular acts of piracy.
Senior naval official Rear Admiral Samuel Alade says piracy has been "drastically reduced" because of what the navy and others are doing.
'War risk area'
Not everyone shares his point of view.
The Norwegian Ship-owners' Association says the number of times its vessels visited Nigerian ports decreased by 37% between 2011 and 2013 because of the threat of attacks, even though port calls to the rest of Africa increased by about 20%.
Underwriters have designated the waters off Nigeria, Togo and Benin a "war risk area", pushing up insurance costs.
This ultimately affects the cost of food, oil and anything else that is transported by sea from West Africa.
Nigeria's multi-pronged approach to tackling piracy has generated confusion, even amongst its own security agencies.
Former Delta warlord, General Boyloaf pictured in his home in Abuja, Nigeria
Nigerian maritime police in October 2013 opened fire on Nigerian naval personnel after mistaking them for pirates.
In March 2014, two British men working for a private maritime security company were arrested and accused of stealing oil.
The strategy of paying former militant leaders to help fight maritime crime is also proving problematic.
One former Delta warlord, General Boyloaf, who led a spectacular attack on a Shell oil platform 120km (74 miles) out to sea, was in August 2014 appointed by the authorities as leader of a maritime security outfit in his home state of Bayelsa.
"The government was having serious security challenges in the creeks," he said.
"They chose me to deal with it as the creeks are my terrain. I was born in the creeks, I fought against the government in the creeks and I will now use that knowledge to hunt the pirates."
But dressed all in white and sitting on a black sofa under an oil painting of a tiger in his villa in the capital Abuja, he complained the government was "choking" funds agreed as part of a 2009 amnesty for the militants.
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