These startling photos top and bottom show a new prototype Mini 6.5m design starting the Mini Pavois solo race from La Rochelle yesterday.

It’s David Raison’s new Mini number 747, Magnum, which he designed himself. The 21ft racer has been two years in the making and is the latest pocket rocket in this excitingly experimental box rule class.

First, a bit of background on Raison himself. He is a French marine engineer and one of the classes long-standing innovators and designer/sailors. He is a hotshot skipper and was 2nd in the 2003 Mini Transat in the production series division.

So his new prototype is aimed at winning rather than merely proving some concepts. But what a weird look it has, with this peculiar rounded, bath-tub shaped bow.

Raison tells me that his thinking was to get a boat as wide and thus as powerful as possible. “The latest boats are at the maximum [dimensions] from the transom to midships and it’s becoming more and more difficult to get a normal bow,” he explains.

“So I decided I don’t care about the bow; I’m trying to get a really wide boat.”

Raison says that part of the inspiration behind it was blunt-bowed US scows. But the scows were never designed that way for hydrodynamic efficiency; it just made them easier and cheaper to build.

So I’m perplexed as to why you’d give away so much waterline length – something you can see quite clearly in the photo above.

“Waterline length is something from the past,” Raison argues. “These open boats aren’t displacement boats any more. Drag is more important. The shorter the waterline length the quicker you can get into [a planing] regime.”

These aren’t the only radical ideas. Magnum has an ultra lightweight rotating carbon wingmast with pre-stretched Dyneema lowers but no jumpers or diamond. At the transom it has kick-up/retractable rudders.

The keel is interesting, too. It cants from side to side and has a telescopic fin so that the bulb can be progressively lowered to the 2m maximum draught allowed by the rule as the keel gets swung out to windward. This is not a completely new idea, as it was first tried in 2003 on a Bouvet-designed Mini.

Unfortunately the blunt-bowed concept is so far unproven. David Raison was forced to pull out of the Mini Pavois on day one when the rudder fuses (the sacrificial low-load lashing for the kick-up mechanism) broke. Raison points out that the boat was launched, without keel system, only ten days ago and “had zero mileage” at the start.

You can see in the photo below that the keel was not fully canted, and the leeward daggerboard not completely lowered to avoid putting them under full load in the windy conditions at the start.

Speaking of his retirement from the race, Raison comments: “It’s not surprising. We had a really fast preparation and things were not tested or calibrated properly. I need to check things progressively. But the boat will definitely be faster.”