Graphic illustration and images captured by a U.S. Navy explosive ordnance disposal team aboard M/T Pacific Zircon, Nov. 16, showing the location where an Iranian-made unmanned aerial vehicle (UAV) penetrated M/T Pacific Zircon’s outer hull during an attack Nov. 15. The one-way UAV attack tore a 30-inch-wide hole in the outer hull on the starboard side of the ship’s stern, just below the main deck. US Navy graphic

The US Naval Institute has a post providing addition detail about the November 15  drone attack on tanker Pacific Zircon.

The primary thrust of the post seems to be, to confirm that the drone was of Iranian origin, but then, that was almost assumed. They seem to have proven that, identifying it as a Shahed-136 design, a “loitering munition.”

For me the new information was where the tanker was targeted and the extent of the resulting damage.

When I first heard that this drone had hit the hull, I thought perhaps the Iranians had decided it was not to their advantage to kill crew members, as had happened in the July 30 attack on the tanker Mercer Street, but apparently that was not the case, since this strike was also on the stern where it is more likely to effect crewmembers.

As to the weapon’s effect, the Shahed–136 reportedly has a 30–50 kilograms (66–110 lb) warhead. referencing a 5th Fleet report, USNI notes,

On Nov. 15, a Shahed 136 explosive-tipped drone flew into the aft section of the merchant oil tanker M/T Pacific Zircon punching a hole through the hull, “while subsequently penetrating and damaging internal compartments. The UAV’s explosive impact also damaged a shipboard boiler, potable water tank and life raft,” reads the statement.

That they managed to damage engineroom equipment, which presumably required penetration of multiple internal bulkheads, after penetrating the hull, is more than I would have expected. The anti-armor, shaped charge version of the munition, which would result in a narrowly focused path of destruction, may have been used.

Another report from Business Insider vis Yahoo that includes more photos here.