The weekly travel trade newspaper, Travel Trade Gazette (TTG), is headlining cruise industry fears after Princess Cruises were forced to divert their ship Grand Princess away from her scheduled visit to the Turkish port of Kusadasi last week - on a warning from the US State Dept - and news that a Syrian man was arrested in Turkey for plotting to blow up an Israeli cruise ship.
These are nightmares which the ever-growing cruise industry has had for years now but dare not speak about for fear of scaring away passengers in their droves.
In fact it is amazing that nobody has really discussed it openly. I can remember thinking about, and talking with colleagues about the obvious opportunities that cruise ships present for terrorists even before Sept 11 2001.
Just imagine: thousands of westerners, particularly Americans who love to cruise and whose cruise companies dominate the industry, all crammed together in one metal box and remote from immediate assistance... which Al Quaeda operative's murderous black heart wouldn't beat faster at the thought?
Of course, cruise ships have now beefed up their on-board security in a big way. Crew and passenger boarding routes are bristling with detectors, so it is more difficult to smuggle a bomb on board.
That would be the most obvious type of attack and simplest. If there's a range of mission alternatives for attacking a cruise ship, the top end might be to try and launch an (ex-Soviet/Chinese) anti-ship missile... but that's way too complicated and prone to mishap or discovery.
So the thing that must absolutely terrify cruise companies and their officers at sea must be the prospect of a small boat, maybe a fishing boat packed with explosives, approaching them while they are offshore - a skill that terrorists and militia in the Middle East have demonstrated before in attacks on tankers in the Gulf and on the USS Cole.
As James Hart, Commissioner of the City of London Police, said earlier this month about the prospect of an attack on his patch: the question is not "if it'll happen". It's "when".