In order to wear a watch while swimming, it needs to be water resistant up to 5 ATM (50 m / 165 ft) at least. For water sports like diving, snorkeling and surfing a water resistance up to 10 ATM (100 m / 330 ft) is required. Delma strongly recommends that leather straps are not to be used in water, rubber straps and metal bracelets on the other hand are fine.

Delma watches with a water resistance of 5 ATM (50 meters /165 ft) or more that have recently been checked, can be cleaned with warm fresh water and a drop of a soft liquid soap, then dried with microfiber cloth. For vintage Delma watches or if you are not sure about the water resistance of the watch being intact, you can moisten a microfiber towel and gently wipe the watch.

Please bear in mind that after swimming and diving in salt water you should always rinse off your watch with fresh water.

The bronze material selected by DELMA for its divers’ watches is a high-quality alloy that is widely used in the marine world and is known for its durability and corrosion resistance. It is normal for bronze to form an oxide layer over time, called patina, a protective skin that covers the metal. Each patina is different, giving each bronze watch a truly unique look. The patina can be removed but it is normal for subtle changes in the color to remain.

Each of our authorized retailers and Delma service centers will change your bracelet or strap for you. All Delma partners and authorized retailers are listed here.

Each DELMA timepiece is meticulously crafted and undergoes thorough testing specifically for you upon receiving your order. This process typically requires an average of 5 working days. Once your DELMA is prepared, it will be shipped using Fedex Intl. Priority Shipping, a reliable service that delivers to most destinations worldwide within 3-5 days. It is advisable to account for a total of 10-12 days for your DELMA to reach you, taking into consideration potential customs inspection procedures that may apply to certain shipments and regions. It's important to note that all our watches are dispatched from our atelier in Switzerland.

Yes, of course. When your package has been dispatched for delivery, you will receive an email containing your delivery tracking number. This will enable you to safely follow the progress of your delivery.

We offer the following payment options at Delma:

Pay securely with Visa or MasterCard. Your payment transaction is protected by an additional two-step password protection service, provided by both Visa and MasterCard Secure Code. This provides you with the best possible credit card data security for your purchase.

We also accept PayPal which covers you with optimal online buyer protection. With a PayPal account, your bank data is protected by the latest encryption technology, so there is no need to enter your card details directly. You’ll be redirected to our webpage to complete your order after the authorization of your purchase.

Direct bank transfers are also accepted.

Delma ships to most countries in Europe, Asia and the Americas. Costs vary based on location.

For Switzerland and EU countries VAT and customs clearance is included. For non-EU countries we will ensure that the relevant customs documents are included alongside your delivery and that your package will be prepared for a smooth customs process, with fully completed customs declaration. Please note that any customs fees incurred in your country of residence will not be covered by Delma. Please contact your local customs office for more information regarding any charges you may incur.

All orders shipped are fully insured.

If you are not thoroughly satisfied with your order, you can return the Delma products purchased on the Website within thirty (30) days following the purchase order date subject to further conditions as detailed in Delma’s Terms and Conditions, which can be accessed here.

Delma products must be returned in their original condition, in a new, unused and perfect state, with all protection tags and stickers attached to them, with the original Delma box and delivery package, including all accessories and documentation. Please also note that we will not be able to accept returns if the product shows signs of wear or has been used or altered from its original condition in any way.

Please note that Delma are unable to refund any bank charges or currency conversion fees you may have incurred from your card provider.

A GMT watch, is a watch that displays both the local time and a second time zone simultaneously. GMT watches were designed to cater to the needs of pilots and frequent travelers. Today, they offer a practical way to keep track of multiple time zones simultaneously, making them highly beneficial for frequent travelers, pilots, and individuals involved in global communication or coordination across different time zones.

Here's a breakdown of how a GMT watch functions:

• Dual Time Zone Display: A GMT watch features an additional hand on the dial, known as the GMT hand. This hand is distinct from the hour, minute, and second hands, often having a different color or an arrow-shaped tip for easy identification.
• 24-Hour Scale: The watch's dial incorporates a 24-hour scale, either as a separate ring or marked on the bezel. This scale enables the tracking of time in the second time zone.
• Independent Adjustable GMT Hand: The GMT hand can be adjusted independently to indicate the time in the desired second time zone. Usually adjusted through the crown of the watch, aligning the GMT hand with the corresponding hour on the 24-hour scale allows easy tracking of the second time zone.
• Local Time and Date: The main hour hand and date display on the watch represent the local time and date in the wearer's current time zone. These components are adjusted as usual, following the local time zone.
• Time Conversion: With the GMT hand indicating the time in a different time zone, users can effortlessly compare and convert between the local time and the second time zone.

Both types of movement are mechanical movements, but are wound in different ways.
Manual-winding or hand-wound watches must be wound by hand using the crown, whereas self-winding or automatic watches are wound by an internal rotor which responds to wrist
movements. 

A bezel is a ring fitted
over the caseband of the watch case. It is used to record additional data. The unidirectional bezel, as its name implies, only turns one way. Unidirectional bezels only rotate in a counterclockwise direction,
ensuring that an accidental bump of the bezel while underwater will cause the diver to surface sooner than planned, never beyond the capacity of their tank. When diving, the bezel marker is set to current time of the minute hand just before entering the water. That way the diver can read the elapsed dive time on the bezel.

A tachymeter, located on the bezel or dial, measures speed based on time traveled over a fixed distance, converting elapsed time (in seconds per unit) to speed (in units per hour).

To measure speed, designate the desired unit of measurement (miles or kilometers) and ensure an accurate representation, such as the distance between two mile markers on a highway.

Here's a step-by-step process:

• Start the chronograph as you pass the first marker.
• Stop the chronograph when you pass the second marker.
• Observe the seconds hand as it travels around the dial, indicating a specific time, such as :45.
• On the outer edge of the dial or bezel, this time aligns
  with a value, for example, 80.

In this case, the aligned value of 80 signifies a speed of 80 miles per hour.