Just discovered this forum, glad to add further details, for anyone interested.
SM Racer was designed in 1991 for the late italian businessman Sergio Mion; Sergio asked me to design the world's fastest endurance monohull and he did not want to use Seatek's. I selected a powerplant of four petrol SC800's, at the time the most reliable high power units that I could try to get immatriculated by Italian Registro Italiano Navale, since the basick block had been built in enough units. I shaked hands with Sergio at the Genoa boat show, also thanks to the positive opinion of Gianfranco Rossi, who told Mion to go ahead with my design; I had pretended that the design would use my own surface drive system, not steering and with independent rudders aft, regardless of how much it would cost to couple the Mercruiser engines to such a system. I delivered plans, a full 1:1 loft plotted on polyester film, to Pierino Crosato on Nautica C4, the selected builder in north east Italy, on Christmas eve. Pierino and his young son Andrea were the only brave man who committed to the building system we specified, i.e. a one off female mould built out of plywood and mirror finished inside, to avoid any kind of hull fairing, both for weight, structural, budget and time issues. These moulds had also to be airtight, since the entire layup was to be vacuum bagged. Six months later, June the 6th, we were testing the rigged boat in Belgium, on river skelde and we did 103.5 knots on our first run, with perfect handling and virtually no porpoising nor chine walking. The RINa officer checked it out and granted us full pleasure homologation, with a regular numberplate, as requested at the time by the endurance rules. We were a few days away from the start of the Martini Endurance Championship, with the first race to be held in Spain. The rules were only than changed, for "safety reasons", and SM Racer was not admitted to race at the first race as it did not comply with the 'new' revised rules. Sergio Mion immediately took the case to Court, asking Martini for a huge amount of money: it was not as easy as it looks, but we were - obviously - allowed to enter the championship, i.e. the Venice Montecarlo. I had been most of the time talking to lawyers, surveyors and the like, explaining why the "safety reasons" were just an excuse of the 'diesel lobby' to rule SM Racer out of Endurance. It is true that the boat was little more than an extremely advanced prototype by the time we started this rough endurance race and we had experienced some youth troubles. Namely, we had some leakage from a structural fuel tank that took a long time to detect. When we started, the crew was not very experienced (including myself), the 'beast' quite a powerful powerhouse and we were plagued by several minor technical problems, like a weakness of the Keikhaefer trim tabs, a leakage from the hydraulic steering pump and a spine compression for Mion during a particularly rough leg. Nevertheless, when most of these troubles where sorted out, on the leg to Ischia, SM Racer (with Eugenio Voltolina on board, as I was exhausted by overnight repairs), SM Racer won without any trouble, leaving la Nueva Argentina way back and setting, at the time, the fastest ever average speed for endurance racing. Now, the boat had 'Victory Design' written all over it, the name of my design company. In Ischia, one year earlier, a catamaran from the Victory Team (UAE) had killed two locals in an accident race; we never knew if this was the reasons why, the morning after, we found the boat damaged by a serious act of sabotage. Someone had damaged with a knife the fuel tank rubber gaskets and while we were lowering the boat into the water, we found over 2000 lts of petrol in the bilge. Leg jumped, police, we empieted the boat, worked overnight for new gaskets, trailed the boat to the next start and still made it on her own bottom to Montecarlo, to the finish line. We had very small structural failures, local weaknesses, that frankly never made us regret to have pioneered the composite way, with an epoxy carbon/kevlar/glass linear pvc and honeycomb core (no balsa anywhere) sandwich laminate, fully vacuum bagged and post cured - in the early nineties this was all feasible, but really not that consolidated; all plans had to be approved by minimum scantlings regulations of the Register and the hull and deck built in four months, including the above mentioned moulds. Also the money budget was ok, but not an open checkbook and all targets were substancially hit. We never had any catastrophic structural failure and never missed aluminium in terms of weight, stiffness, low cg, fairness, overall freedom of shape if compared with my exthensive previous experience both at Cougar UK and at Stain in Italy with several Class1 Mono's and Cats. After the race, I did not take any holiday, but worked with the yard to make several minor (in design terms) but vital improvements, mainly to the rigging. Once in Cowes, the boat simply started in the lead, then let Scioli go ahead for a few miles and once they realized that La Nueva Argentina had no more to show, took the lead and finished there, setting a bunch of new records including the overall fastest race at 91.6 mph average speed, a record that the boat still hold today after 20 years. I am very grateful to Sergio Mion , Beppe Amati and Robin Culpman - navigator for the day - for doing such an excellent race. One engine lost a supercharger belt early in the race and the Trimble navigator died almost half race. But they played it wisely, some really good video show a boat that at over 120 mph looks very stable and safe. The following us experience was not followed by myself and Sergio did not meet the right people. There were never structural failures, to my knowledge, in the States. I did a survey later on, to show how badly the rigging had been done by a Miami based shop, who did damage the structure to fit bigger pulleys and parts that were bolted onto the original engines to try and increase the power. When we test benched one of these 'modified' units, it did not give even the original 800 hp's: it was a total rip-off the ended up in court. This nasty guy also started questioning that the boat was not performing because it needed improvements, not because he had screwed up the engines: therefore he started 'glueing and nailing' additional spray rails and I think this might have been the cause for thinking there were structural failures, as these spray rails were of course tearing off even during trials. We later modified it into a pleasure boat, thanks to Peter Hledin work and restored the engines by Mike D'Anniballe and it still did over 120 mphs as it was tested in Venice, back in Italy. Sergio died later of cancer and the wife sold the boat to Rizzardi and it still is around Sabaudia, nearby Rome. A really good boat, worth very nice comments by Daniel Savitsky, who I was lucky and privileged enough to 'lecture', in NY at a SNAME meeting. Still today, in some filed work we do for the defense industry, I pick a lot of data learned from SM Racer. At the time, one of the world's fastest monohull and a very good boat by the judment of many talented pilots, Steve Curtis and Lino di Biase amongst them.