|Time zone||GMT +1 (DST: GMT +2)|
|Major events||Grand Prix motorcycle racing|
|Length||6.000 km (3.728 mi)|
Opatija Circuit, also known as Preluk Circuit, was a motorsport street circuit located in Opatija, Croatia. The circuit used the city streets of the seaside resort on the Kvarner Gulf between 1931 and 1977. It was known as the "Monaco" of the Grand Prix motorcycle racing circuit because of its dramatic views of the Adriatic Sea.
The circuit first hosted local auto races beginning in 1931 when Opatija was known as Abazzia and was under temporary Italian rule. It has alternately been known as the "Circuito di Abbazia" (Opatija Circuit) and the "Circuito di Carnaro" (Kvarner Circuit). The circuit's layout was comparable to that of the Monaco Grand Prix course but faster and longer at 6 kilometers in length and with 85 meters of elevation changes. The race course presented an impressive challenge for competitors as it followed the corniche along the shoreline, then began to climb as it hugged the hillside above the town before descending back down to the coast.
The venue first gained international prominence when it hosted the 1939 Adriatic Grand Prix won by Luigi Villoresi driving a Maserati 4CL. The area became part of Yugoslavia after the Second World War. Racing resumed after the war with local motorcycle races being held in 1946. The following year, the circuit hosted a round of the Yugoslavian motorcycle national championship. By 1950 car racing also returned with sportscar races between 1950 and 1959, Formula Junior races in 1960, 1961 and 1963, and Formula 3 races between 1964 and 1968.
In 1961, the 50cc race formed the fifth round of the FIM European Championships, won by German rider Hans-Georg Anscheidt on a Kreidler. From 1969 to 1977, the venue hosted the Yugoslavian Grand Prix as part of the Grand Prix motorcycle racing world championship. When Godfrey Nash rode a Norton Manx to victory at the 1969 Yugoslavian Grand Prix at Opatija, it marked the last victory for a single-cylinder machine in a 500cc Grand Prix.
Despite the circuit's scenic setting, it was an unsafe race track due to high speeds on narrow roads coupled with numerous unmovable roadside obstacles, such as trees, stone walls, lampposts, electric poles, embankments, houses, and the Adriatic Sea. In this regard, the circuit gained a reputation similar to that of the Isle of Man TT circuit. The safety situation became untenable for cars and the last auto race held on the circuit was the 1968 Formula 3 Gran Premio Adriatico won by Manfred Mohr driving a Tecno 68. Despite the risks, motorcycle races continued to be held.
During the 1973 motorcycle racing season, in the aftermath of the deaths of Jarno Saarinen and Renzo Pasolini at the Nations Grand Prix, several racing teams including Yamaha, Harley Davidson and MV Agusta, boycotted the Yugoslavian Grand Prix due to unsafe track conditions. Other riders chose to compete, but with less than their full efforts. In 1974, British rider Billie Nelson crashed into the crowd during the 250cc race, injuring several spectators. He died later that night at a hospital.
The Yugoslavian Grand Prix promoters had received an ultimatum from the FIM before the 1977 Yugoslavian Grand Prix race that, if they did not improve the safety of the circuit, the event would be canceled. The event was a disaster with Italian rider, Giovanni Ziggiotto, crashing during practice for the 250cc race when his motorcycle's engine seized and he was hit from behind by Per-Edward Carlson. He died four days later in a hospital. During the 50 cc race, Ulrich Graf crashed when his bike developed a rear tire puncture and he was thrown into a rock wall. He suffered serious head injuries and died later in a hospital. The tragedy forced the venue off the Grand Prix schedule and the Yugoslavian Grand Prix was moved to the Rijeka Circuit for the 1978 season.
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