The original rubber dive watch strap.
Worn by divers since 1955.
ABOUT THE ORIGINAL TROPIC®
THE LEGEND OF THE TROPIC® STRAP
The proprietary vulcanized rubber used to produce each Genuine TROPIC® Rubber Strap is hypoallergenic, and optimized for tensile strength, UV resistance, and is largely immune to adverse effects from extreme heat or cold. And since this rubber contains no silicone, it does not attract dust or fade from prolonged exposure to sunlight.
This new Genuine TROPIC® strap carries the torch of its mid-century pioneer, preserving the iconic texture, silhouette, and striking retro aesthetic, while improving on the overall durability and comfort that have made the TROPIC® straps a beloved sports watch essential for over 50 years.
UPS PRIORITY
GUARANTEED
Since 1955
Worn by the brands that defined dive watches
By the mid-1950s, dive watch makers were looking for a rubber strap that could match the watches they were building for divers, fishermen, spearfishers, and the first generation of recreational scuba. The answer was the TROPIC®, a perforated, basket-weave vulcanized rubber strap waterproof to the same depth as the watch itself.
This 1950s advertisement for the LIP-Blancpain “Étanche jusqu’à 60 mètres” (waterproof to 60 metres) shows the strap on the réf. 9294 amateur diver. It is one of dozens of period dive watches that left the factory on a TROPIC®.
Original advertisement courtesy of LIP BESANÇON.
How it’s made
Vulcanized rubber, the original way
Every TROPIC® strap starts as a sheet of vulcanized rubber compounded to a recipe Synchron developed specifically to recreate the feel of the original 1955 strap, and to outlast it. The compound is pressed into the same basket-weave pattern the strap has carried since the beginning. The pattern is more than decoration: the weave releases sweat from the wrist and lets water escape after a dive, which is why divers in the 1960s preferred it over the solid rubber of the era.
After moulding, every strap is hand-inspected for flash, surface defects, and dimensional accuracy. Strap thickness, taper, and hole alignment are checked against a master tool that has been in service since the early Synchron production runs.
Why we don’t use silicone, PFAs, or shortcuts
Most “Tropic-style” straps on the market today are silicone, not rubber. Silicone is cheaper to mould, but it attracts lint, hardens in UV light, and has a soft, tacky feel many wearers don’t enjoy after the first month. We use vulcanized rubber. It is closer in chemistry to the original 1950s formulation, more comfortable in heat, and more durable across years of wear.
We also exclude PFAs (per- and polyfluoroalkyl substances, sometimes called “forever chemicals”) from the entire compound. PFAs are common in industrial rubber processing because they improve mould release. They are also persistent environmental contaminants and a regulated concern across the EU and US. Our formulation reaches the same surface quality without them.
The buckle nobody copies correctly
The TROPIC® buckle has a near-90-degree bend a few millimetres behind the pin. It exists for one reason: when the strap is fastened, the buckle lies flat against the wrist rather than standing proud. On the dive watches the strap was first paired with (in some cases worn over a wetsuit), that small geometric difference was the difference between a comfortable hour underwater and a hot spot at the wrist.
The bend is also the easiest thing to skip. Most rubber-strap manufacturers use a generic straight buckle because it’s cheaper to stock. Our buckle is made specifically for the TROPIC® and is included with every strap, in 16 mm or 18 mm to match the strap’s taper.