Nato navies operating off the coast of Somalia have warned of a recent increase in maritime piracy. I decided to experience first-hand what seafarers go through.
I joined them not on a warship - which pirates avoid - but on a merchant tanker, the 112,000-tonne MT Sea Legend, carrying 90,000 tonnes of gas oil from the Gulf of Oman, through the Gulf of Aden between Yemen and Somalia, past the Bab al-Mandab Strait and up the Red Sea to Suez.
It is a 2,628-mile, eight-day voyage that sailors call "the route of fear".
Several ships have been approached and attacked in the past few days. More than 100 sailors are still being held to ransom on the Somali coast.
Yet close to 20,000 ships sail through the critical choke point at the bottom of the Red Sea every year, carrying vital trade.
The ship I joined is one of an increasing number using armed security teams onboard, this one provided by the Dorset-based company Neptune Maritime Security.
Within 24 hours of leaving port in Oman they have set up a sentry roster, ordered extra coils of razor wire to be strung out along the deck, and test-fired their high-powered rifles from the balconies next to the bridge.
Mark Eassom, a former Royal Marines sergeant-major, is the team leader.
He says oncoming pirate boats, called skiffs, can come in incredibly fast but that his team has a system of graduated response.
"Once we've gone through all the other escalation methods and we've deemed that weapons is our final choice we'll fire several warning shots near to the skiffs but not endangering them at all.
"The use of lethal force is an extreme and very last resort."
The voyage starts uneventfully. We steam out into the Gulf of Oman and skirt round the south-east corner of the Arabian Peninsular. Dolphins appear off the bow and a large white seabird glides past.
Then we are in the Arabian Sea where numerous ships have been approached by pirates and some successfully hijacked.
We enter the sea lane between Yemen and Somalia where a coalition of 25 navies have set up a convoy system to escort vulnerable shipping through the Gulf of Aden.
It is 580 miles long and we are given a Chinese Navy frigate, steaming just one mile off our port bow. Three miles away the convoy sights what everyone suspects is a PAG, a Pirate Action Group, a wooden dhow and 3 skiffs alongside.
But whether innocent fishermen or lurking pirates it takes no action, the Chinese frigate is an imposing presence.
After two days the convoy breaks up as planned, the Chinese warship turns back and we enter the most dangerous part of the voyage alone.
Just off Djibouti, steaming north, there is a sudden commotion on the bridge, everyone is staring ahead through binoculars.
The cargo ship ahead of us has just radioed in a suspected PAG heading towards them.
I look through the binoculars and see two wooden dhows and two fast skiffs cutting a course between our bow and the ship ahead.
The captain sounds the foghorn, activates the firehoses on deck, summons the security team and gets on the tannoy.
"Security Alert. Suspected Pirates approaching. Code Yellow. Code Yellow."
Skiffs like these are often seen in these waters
This is the signal for most of the crew to muster inside next to the "citadel", the safe room we will all have to shelter in if pirates ever manage to get onboard.
Outside on the bridge wings the security team are training their rifles on the suspect vessels now circling round us.
The team leader raises his rifle above his head to show whoever is in the boats there is an armed security team onboard and therefore not worth attacking. The boats back off, crisis averted.
The seas here are full of such craft. They look tiny from up on the bridge but pirates are adept at using them to sneak up on ships as big as a supertanker, scale the sides, take them over and demand multi-million dollar ransoms.
Melvin Tayon is 2nd Engineer on the Sea Legend, the ship we are travelling on.
He is still haunted by a narrow escape on another ship that did not have any security onboard.
"Four times they fired RPG, rocket-propelled grenade," he tells me, "also they fired this Kalashnikov rifle which they call AK47".
Using armed protection teams at sea is controversial; not everyone is in favour.
Ships are increasingly travelling in convoy
Recently Italian marines mistakenly shot and killed innocent Indian fishermen.
There is concern that in the wrong hands there could be more such blunders and there is still no universal set of rules of engagement, although these are in the pipeline.
But the owners of this ship, Arab Maritime Petroleum Transport Co, make it a policy to always put armed teams on this dangerous route.
Capt Abdulrahman Sharaf is unequivocal.
"It makes a very big difference having an armed security team onboard.
"The High Risk Area has become huge, covering the Arabian Sea, the northern Indian Ocean, and the south of the Red Sea. So far no ships have reported being hijacked having armed force onboard.
"Some flag states don't allow armed guards which is no good for seafarers because they have no protection."
Piracy off Somalia is down from last year's record levels, but it shows no sign of stopping.
As we sail north through the Bab al-Mandab Strait up into the Red Sea another report comes in of an attempted hijacking.
Until Somalia's problems can be solved on land its clear that the pressure on ship owners to provide armed guards for this route looks set to increase, as seafarers continue to run the gauntlet of some of the world's most dangerous sea lanes.
Source: BBC News, Frank Gardner