International Tempest Information, Review, Specs

Sailing Performance & Handling

The International Tempest is frequently described by its proponents as a "keelboat that thinks it’s a dinghy." This characteristic is driven by its technical ratios, specifically a Displacement/Length (D/L) ratio of approximately 57, which places it firmly in the "ultra-light racer" category. According to technical data from World Sailing, the boat displaces just 1,021 lbs, nearly 45% of which is concentrated in its 440-lb lead bulb keel. This high ballast ratio provides the stability required to carry a generous 247 square feet of sail area, while its slender 6'4" beam (Length-to-Beam ratio of 3.39) allows for a "needle-like" hull shape that excels in both light air and heavy planing conditions.

Handling the Tempest requires a high degree of athleticism. It is a two-person boat where the crew is equipped with a trapeze to provide leverage against the heeling force—a rare feature for a keelboat. The rig is equally sophisticated, featuring a "bendy" mast designed to de-power the mainsail in high winds. Anecdotes from the U.S. Tempest Class Association highlight that the boat is exceptionally responsive to sail trim, capable of planing upwind in a breeze, yet stable enough to be pushed hard downwind under its large spinnaker without the "death rolls" common to more traditional designs like the Star.

Popular Mentions & Media

The International Tempest’s primary claim to fame is its tenure as an Olympic class. It made its debut at the 1972 Munich Olympics (with sailing events held in Kiel) and returned for the 1976 Montreal Olympics (held in Kingston, Ontario). During this era, it was the vessel of choice for some of the world’s most elite sailors, including legendary designer and helmsman Ian Proctor himself. Although it was eventually dropped from the Olympic roster in favor of the Star, it maintained a strong cultural footprint in the racing community as a "fairer" one-design alternative to the Star, largely due to its strict construction rules and more modern hull form.

Known Issues & Buyer’s Checklist

Prospective buyers of older Tempests—particularly those built in the late 1960s and early 1970s—should prioritize a few technical areas during inspection. Data synthesized from technical discussions at Sailing Anarchy and the class associations suggest the following "gotchas":

• Keel Fin Corrosion: On early models, the keel blade was often constructed of steel rather than the preferred stainless or encapsulated lead. These blades are prone to rust, especially if the boat was kept in salt water. If the keel is stuck in its lifting box, it often indicates significant internal corrosion.
• O’Day Hull "Softness": There is a documented discrepancy in the longevity of early US-built O’Day hulls compared to the later European builds by Mader. Experts note that older O’Day decks and hull bottoms near the mast step can become "soft" or delaminated due to the extreme rigging tensions required for competitive racing.
• Mast Step and Bulkhead Stress: The Tempest uses a highly tensioned rig. Check the integrity of the mast step and the three transverse bulkheads that provide the boat’s structural rigidity and emergency buoyancy. Stress cracks in the gelcoat around these areas are common and can indicate structural fatigue.
• Bendy Mast Integrity: The specific Proctor-designed masts were engineered to flex significantly. Ensure the mast has not been "over-bent" or permanently kinked, as finding a period-accurate replacement can be difficult and expensive.

Community & Resources

The boat continues to enjoy a dedicated following, particularly in Central Europe and the United States. The International Tempest Class Association serves as the global governing body, maintaining the strict one-design rules and organizing the World Championships. In North America, the U.S. Tempest Class Association remains the primary hub for owners, offering technical wikis on restorations and rigging modernizations, such as the transition to Dyneema running rigging and updated jib lead systems.

The Verdict

The International Tempest remains one of the most exciting "pocket" keelboats ever designed, offering dinghy-like speed with the safety of a weighted bulb.

Pros:

• Exceptional performance and planing capability for a keelboat.
• The trapeze provides a unique and athletic sailing experience for the crew.
• Strict one-design rules ensure that older boats can still be competitive with minor upgrades.
• Easily trailerable thanks to its retractable fin keel and light displacement.

Cons:

• Requires a highly skilled and physically active two-person crew.
• Older hulls (pre-1980s) may suffer from structural "softness" or keel rust.
• Limited class racing outside of specific regional hubs in the U.S. and Europe.