The 2,824-TEU feeder GFS Pride sank off Oman on Tuesday after an unknown projectile started a fire the crew couldn't contain. All 21 seafarers evacuated safely. That's the headline. The fine print is worse for shippers.

Maritime authorities counted at least 10 vessels attacked in or near the Strait of Hormuz since Sunday. Six incidents occurred on Sunday alone — the highest one-day total since the U.S.-Iran war began in February. UKMTO, the British security monitor, logged 12 attacks between Oct. 5 and Oct. 11, the largest weekly tally of the conflict, after 10 the week before.

The GFS Pride wasn't alone among boxships. A second Singapore-flagged feeder, the GFS Giselle, took projectile hits and suffered hull damage but reached safe anchorage under its own power; its 22 crew were reported safe. Two other feeder vessels were struck, including the 2,500-TEU DP World Kaveri, operated by a unit of Dubai's DP World.

According to the IMO's casualty data, the GFS Pride is the third vessel to sink since the war started. The second was the Antigua and Barbuda-flagged bulk carrier Cape Dao, which went down after being struck on Sept. 23.

Whose account of the sinking holds up?

Iran's Islamic Revolutionary Guard Corps claims the GFS Pride hit a naval mine on an "unauthorized" route and was carrying contraband. Singapore's Maritime and Port Authority disagrees, saying the ship was struck by projectiles. CNN reported that experts assessed a drone strike as the more likely cause. Pick your version, but the vessel is on the bottom either way.

What does this change for shippers with cargo on feeders?

Plenty, and not just in the Gulf. Analyst Lars Jensen pointed out that carriers may have bought slots on the attacked vessels — Maersk (OTC: AMKBY), Ocean Network Express, PIL and OOCL all showed active schedules for some of the ships.

That matters because of a clause most cargo owners read once and forget. Analysts note war insurance can be cancelled on short notice if cargo moves on a vessel not owned by the carrier named on the bill of lading. Slot-chartered feeder cargo is exactly that scenario. If you booked with a major line and your box rode a feeder, your cover may be thinner than you assumed.

Traffic is already thinning

Kpler counted 131 crossings through the strait in the week ended Oct. 14, down from 176 the previous week — a drop of roughly a quarter. The firm cautioned the decline isn't solely attributable to the latest attacks. Even so, the direction is unmistakable.

Crude flows tell the same story. Kpler estimated 12.6 million barrels per day moved through the strait on Oct. 13, down from roughly 15 million barrels per day at the end of September. That's about 2.4 million barrels a day gone in a fortnight — the equivalent of losing the daily output of a mid-sized OPEC producer.

Iran has linked the intensified campaign to the U.S. blockade of its ports and tougher sanctions. U.S. Central Command, for its part, said commercial traffic continues through the strait under coordinated protection from American forces and regional partners. Both statements can be true; neither protects a feeder from a drone.

For carriers, the calculus now includes hull losses, not just delays. For forwarders, it's time to check whose tonnage is actually lifting the boxes. And for shippers whose insurance hinges on the bill of lading carrier, the fine print just got expensive.

With attack counts setting weekly records and transits falling, expect war-risk premiums and routing decisions to harden further before any de-escalation — which, on current evidence, awaits a political settlement nobody has delivered.