Hands-on with the U-Boat's U-1001 diver's watch

During a meeting I had with Italo Fontana, owner and designer of U-Boat Italy, he expressed his infatuation with professional instruments. The fact that watches are instruments used to measure time, explains why so many watch designers feel the same way. Bell & Ross and Giuliano Mazzuoli are obvious examples that come to mind. The U-Boat U-1001 is a watch that pays tribute to Mr. Fontana’s passion. It is built to withstand the rigorous demands of professional diving and it offers a bold, clear, technical design reminiscent of high tech instruments.


A water resistance rating of 1000 meters – 1001 meters to be true to the U-Boat spec sheet – is not easily acquired. It is easy to see why when considering that at a depth of 1000 meters, a watch is subject to an atmospheric pressure that is 100 times superior to that at sea level. This translates to about 150 pounds of force per square inch. In order to survive this tremendous pressure a timepiece needs a strong case, which in this instance is a 55mm tank carved out of titanium. The designers and engineers then have to take into consideration all the weak spots of the watch like the crystal, crowns, and all the other tiny fissures between parts. The next few paragraphs will look at each of these parts in detail.

The U-1001 cannot actually be classified as a professional diving watch due to its lack of certain diving-related markings, but all structural qualifications are met. One very important aspect of the U-1001/1 is its crystal. In order to withstand the incredible pressure pushing down on it, it must be made extraordinarily thick. It is constructed out of synthetic sapphire, which is is highly scratch resistant due to its hardness, and it is 5.5mm thick. Because it is flat it does not distort the dial’s features, so its thickness is not evident by looking at the watch straight on. Consider that at 1000 meters bellow sea-level the crystal alone is supporting the equivalent of about 400 lbs. Looking at it that way may give a whole new appreciation of how strong diving watches have to be. This strength indicates durability and quality on dry land.

Another technical feature that is fitted to almost every diving watch is an automatic pressure release valve. On the U-Boat U-1001/1 it is placed below the crown on the left side of the case. Apart from the coolness factor that it adds to the overall look of the watch, this small valve has a very specific function. While its name implies that there is helium gas within the watch, what it is referring to is the helium that is present in “breathing gas” mixtures used by professional divers for very deep dives. Helium and Nitrogen, being very small molecules are able to seep into the watch through the seals while the diver is acclimatizing in a chamber filled with the gas mixture. At the point when the watch returns to the surface said gases expand and may cause great damage to the watch. The crystal may become dislodged or shatter, and a weak case would be at risk of deformation. The helium valve therefore is appointed to evacuate the gas and relieve the internal pressure.

Now that we have shown the structural integrity of the U-1001, we can concentrate on what is more visible about the watch. As in many U-Boat watches the size of the case is quite remarkable. Its impressive 55mm diameter is complemented by an thickness of 18.2mm. When working at the Matt Baily watch boutique in Montreal Canada, I would always tell my clients that there is no such thing as a watch that is too big. When it comes to 55 millimeters, however, I received some incredulous stares. The truth is that this giant wrist-watch is comfortable on any size wrist, but a passion for oversized watches is certainly prerequisite.

The case is made of titanium. The lightness of the substance marries well with oversize watches. U-Boat’s U-1001 is deceptively light for this reason. The bezel distinguishes this model from the first generation Classico U-1001s. It is raised above the crystal as in the company’s Flighdeck models. The crown cover is found, as usual, on the left of the watch case and is neighboured by the helium escape valve. The crown cover is held to the case by a hinge like that on a Cartier Pascha if the Pascha were submitted to intense MMA training for several years. The actual crown that it protects is robust nonetheless. It is quite large, and is solid in all setting, winding, and rest positions. The engraving and finish of the case, including the black PVD coating are basic yet masterful showing off the manufacturing prowess of the U-Boat watch factory in Lucca, Italy. The U-1001 is a good representative of the Florentine tradition of watch case manufacturing.

As with the original version of the U-1001, U-Boat will offer three dial variations. A black “U-1001” inscription is applied between twelve and three o’clock and hour markers display the different colors: beige, orange, or blue. This style of multilevel dial is sometimes referred to as the Sandwich dial. The colored plate lies underneath the black dial that has the hour markers stencilled out of it. Sandwich dials were introduced in the forties for Navy Commando watches. The stencilled out, recessed hour markers were filled with luminous powder for unparallelled visibility in the dark, whereas now the entire bottom plate is phosphorescent.

Finally, the strap completes the waterproof nature of the watch. An impermeable black rubber band is fitted with a decorative, titanium plate and a heavy duty folding deployante clasp. The clasp, which can be opened, or deployed, by way of two pushers, is also equipped with an easy to use mechanism for sizing. Unfastening the “tongue” and sliding the buckle up or down the strap adjusts the band’s length.

A Swiss automatic movement powers the U-Boat U-1001. While still a very important quality feature, it is dwarfed both literally and figuratively by the U-1001’s imposing case and features. It is provided by the infamous, Swiss manufacturer ETA. Based on the 2824-2 calibre, the mechanism is modified slightly to U-Boat specifications and the rotor is decorated with Côte de Genève finishing. This is not a very exotic or particularly interesting movement, but it is as robust and reliable as the rest of the U-1001.

Italo Fontana is a passionate designer. He captures what he loves in his creations and backs it up with quality and luxury. Luckily for him many watch lovers share the same esthetic predilections.

Marco is a specialist of U-Boat watches. at Matt Baily.