The BBC's Jonah Fisher has joined British Royal Navy frigate HMS Northumberland as it patrols the Gulf of Aden in an EU taskforce to deter Somali pirates.
In the second instalment of his diary from the ship's deck, our correspondent joins a helicopter patrol.
FRIDAY 20 FEBRUARY
A trip in the Merlin helicopter provided the perfect opportunity to see how hard it is to tackle Somali piracy.
Jonah Fisher joins a helicopter hunt for Somali pirates
This is one of the busiest shipping lanes in the world, with huge container ships and tankers making their way to and from the Suez Canal.
But there are also lots of much smaller local ships here, and almost all of them match the initial profile of "Somali pirate ship".
That means a wooden dhow with fast-moving motorised skiffs attached alongside.
From high in the sky ships that could hardly be seen with the naked eye were magnified through a powerful video camera mounted on the outside of the helicopter.
I watched as the operator skilfully zoomed in, trying to look for secondary clues that the boats might be more than just fishing vessels.
The key indicators are the presence of ladders or grapple hooks which the pirates use to climb from the skiffs onto the hijacked ship.
On the deck of HMS Northumberland
Large numbers of men - far too many for a fishing trip - is another sign, as is lots of fuel on board that the pirates can use as they wait at sea for their target to come along.
But you wouldn't have to be the cleverest Somali pirate captain to stash your ladders and fuel out of sight and to keep as many of your men as possible under a tarpaulin.
So most of the local ships we checked out from the air were inconclusive.
Nothing to warrant sending the Royal Marines in their speed boats - but impossible to say with conviction that they were not pirates.
It's clear that the sailors on board HMS Northumberland are keen for action.
For two hours late on Thursday a real buzz went around the ship as it was briefly diverted to intercept a drug-running ship. But the information turned out to be old.
Then today the Royal Marines got kitted up to go and check out some local fisherman.
Unfortunately for them the chances of an act of piracy taking place close enough to the Northumberland for it to act are pretty slim.
Deterrence is a big part of the role of the EU Atalanta taskforce - and it seems that in the areas that they operate the warships are having an effect.
This afternoon the biggest gun on the ship - with shells four-and-a-half inches wide - was fired in a training exercise.
If pirates were watching they would have been impressed.
But with between just 10 and 15 warships in the region, most of the one million square miles around Somalia are still perfect for bounty hunting.