Three Traditional Races 
Since the end of World War II, Detroit (Michigan), Madison (Indiana), and Seattle (Washington) have reigned as the three traditional stopovers on the APBA Unlimited hydroplane tour.
A fourth city, Washington, D.C., likewise served as a traditional race location in the post-war era. But D.C. has not hosted an Unlimited event since 1977.
Madison Regatta, Inc., is actually the senior Unlimited committee on the basis of having hosted a Thunderboat race every year since 1950. Detroit hasn't missed a year since 1946. But the current Detroit committee--the Spirit Of Detroit Thunderfest--wasn't organized until 1962. Between 1946 and 1961, the Motor City traditionally hosted two Unlimited events per year. The Detroit Yacht Club sponsored the Silver Cup, while the Windmill Pointe Yacht Club offered the Detroit Memorial Regatta. Both the DYC and the WPYC dropped out of the sport when prize money became mandatory at all Unlimited races, starting in 1962.
The Spirit Of Detroit Association was hurriedly formed in the summer of 1962 and, within the space of about six weeks, hosted the Spirit Of Detroit Trophy. The winner was Bill Muncey in U-60 Miss Century 21 (nee Miss Thriftway), which won all three heats.
Madison Regatta, Inc., formerly known as the Madison Boat Club, staged an unsanctioned Limited regatta in the fall of 1949. The largest class that competed was the 225 Cubic Inch inboards. In 1950, an APBA sanction was obtained for the first time from the American Power Boat Association. The APBA referee was Jim Noonan, father of UHRA referees Jim and Billy Noonan. The highlight of the 1950 regatta was a 15-mile one-heat free-for-all. The U-16 My Darling, a Rolls-Royce Merlin-powered step hydroplane, owned and driven by Andy Marcy from Springfield (Illinois), took the top honor.
Seattle's Unlimited debut occurred in 1951. The Seattle race was co-sponsored through 1960 by the Seattle Yacht Club. Greater Seattle, Inc. (later renamed Seafair, Inc.) became the sole sponsor of the race, starting in 1961. The Seafair Boat Club, which administers the Seattle race on Seafair's behalf, was organized in 1975.
The 1951 schedule originally called for two major Unlimited events to be run in Seattle--the Gold Cup on Saturday, August 4, and the Seafair Trophy on Sunday, August 12. Both races were won by the brand new U-37 Slo-mo-shun V, driven on August 4 by Lou Fageol and on August 12 by designer Ted Jones.
Unfortunately, all of the out-of-town challengers went home after the Gold Cup in 1951. And the Portland-based Quicksilver from Oregon crashed to the bottom of Lake Washington with fatal consequences to its driver (Orth Mathiot) and riding mechanic (Thom Whittaker).
The 1951 Seafair Trophy had only the hometown Slo-mo-shun IV and Slo-mo-shun V from the Unlimited Class. So, a trio of 135 Cubic Inch inboards filled out the field so that the race could count for records.
After Madison, Seattle, and Detroit, the next oldest Unlimited race sites are San Diego (California), which started in 1964, and the Tri-Cities (Washington), which commenced in 1966. The Tri-Cities has an unbroken string of 33 races in 33 years. San Diego has also hosted 33 Thunderboat contests but briefly dropped off the circuit during 1971 and 1972.
Kelowna, B.C., ran a couple of races during 1966 and 1967, but then dropped off the tour and didn't return until 1996.
Las Vegas (Nevada) hosted a single Unlimited event in November of 1950. The Thunderboats next ran there between 1956 and 1960 and did not return until new management revived the race in 1986.
Evansville (Indiana), a pre-World War II race site, joined the Thunder Tour in 1979 and has hosted the Unlimiteds for twenty consecutive years under the sponsorship of the Freedom Festival.
Honolulu (Hawaii), which debuted in 1990, and Norfolk (Virginia), which started in 1997, are comparative newcomers to Unlimited hydroplaning.
Scheduled to join the Thunderboat fraternity are Barrie (Ontario) and Lake Havasu City (Arizona). Both will host their first-ever Unlimited races in 1999.