Bladerunner 51, the British racing boat that Iran uses today.

From England to Iran, via South Africa. This is how this incredible hull made its way around the world, transforming from a competition boat to an assault vessel. We retrace the story of a project that is as peculiar as it is successful, whose events transcended the simple nautical dimension.

The record

On the morning of August 12, 2005, the Round Britain 2005 team, consisting of Neil McGrigor, Tony Jenvey, Jeremy Watts, and John Guille aboard the“Bradstone Challenger,” a 51-foot Bladerunner speedboat, broke the overall world record for the fastest speedboat circumnavigation of Great Britain, completing the 1460-nautical-mile circumnavigation in 27 hours and 10 minutes at an average speed, including fuel stops, of more than 53 knots, breaking the existing record of 3 hours and 41 minutes.

Bladerunner 51

But what is so special about this vessel that makes it stand out among the vast array of fast boats? To make a record over a long distance, especially in sea areas subject to harsh weather conditions such as those surrounding the British Isles, you need a hull that can go fast on the calm as well as, and especially, on the rough. This is the problem faced by all great nautical designers, foremost among them the legendary Renato “Sonny” Levi, who staked everything on the inverted tricycle configuration: a catamaran at the bow, which “traps” air underneath to produce lift, and then becomes a monohull toward the stern.

A three-point hull, then: faster than any monohull on the calm, faster than any catamaran on the rough. Here, Bladerunner 51, designed by Lorne Campbell, achieves the same goal with a hull halfway between traditional tricycle (not inverted), like Thunder Child II, and a trimaran. In fact, the builder, ICE Marine, calls it “Air Entrapment Monohull,” meaning air entrapment monohull.

The two side fairings, in fact, help to create lift not so much by their thrust, but by creating a barrier that blocks the air in the two tunnels that are created. It is this “air cushion” that goes to increase lift and reduce friction with the water, somewhat like the miniskirts in the ground effect F1s of the early 1980s. Also, like seaplane boots, they have the not insignificant advantage of offering a lot of transverse stability.

The new life (military)

And here, Iran comes in. A boat that is very fast in all conditions, and designed for stability: why not use it as a weapon? While this reasoning may surprise us, it must be put into context. The navy of the Revolutionary Guards, the Pasdaran, has set up a military doctrine for maritime warfare based on the thin ship, i.e., consisting of many small, fast vessels, to deal asymmetrically with far more organized navies and close the Strait of Hormuz, Iran’s real deterrence. And the record achieved by the Bradstone Challenger must have aroused its interest as a fast and stable platform on which to install armament.

They then attempt to buy it to copy its distinctive hull geometries, but the West vetoes it. Through a South African arms dealer, they manage to get their hands on it in 2009. Rumor has it that the U.S. even considered boarding the freighter carrying the shipment!

Finally, in 2010, a class of assault speedboat known as the Seraj-1 was derived. It is not known how many units were produced, but among the endless array of fast boats available to the Pasdaran, this remains perhaps the most nautically distinctive.