D4 USA Solar Diver Care and Handling Guide

D4 USA Solar Diver Care and Handling Guide

This article provides a comprehensive overview of the Vaer D4 wristwatch and instructions for its operation and use.

I) Product Summary

The Vaer D4 USA Solar Diver is a solar-powered 20ATM tool watch, powered by an Epson VS-22 movement and assembled in the United States of America. Blending the sophistication and refinement of a luxury dive watch with the outdoor specifications and perpetual timekeeping of a true tool watch, the D4 collection is designed as the ideal “everyday wearer”.

First launched in the summer of 2021 as a follow-up to our popular automatic collection, the D4 is built on the same core platform as the D5 (sapphire crystal, 20ATM, USA-assembled) - yet with a rare and often sought after solar powered movement that is very difficult to find in the modern watch market. Like the D5 before it, we had three key goals in mind in designing the D4 series:

  1. A Sub-$400 Price Point
  2. 20ATM + Waterproof Warranty
  3. Full USA Assembly and Testing


In our opinion, these three factors make the D4 collection a very distinctive option in the highly competitive sub-$1000 dive watch category, and place it firmly in the middle of the market between mass produced Chinese made dive watches (from Timex, Fossil, MVMT and Asia-based microbrands) and far more expensive "luxury" options (from the likes of Tudor, Tag Heuer, Oris, Sinn, Shinola etc.).

The D4’s USA assembly make it a far more distinctive and personalized craft good than of its Asian mass-market competitors, yet it still represents a significant value over more expensive options which carry a luxury markup and typically lack functional outdoor features (such as perpetual timekeeping, or a waterproof warranty).

In simple terms, it has everything you’d want in an everyday dive watch, and nothing you don’t. USA assembly gives it a strong sense of character and identity, but it also has the price-point and feature set you’d want for watch that you can wear for years (in the most extreme outdoor conditions).

"In my opinion, the D4 is one of the best one-watch solutions on the market today. It has the on-wrist presence and sophistication of a collector-worthy vintage 70s diver, while also offering the practicality of and economically sensible of a modern tool watch. It's sort of like a vintage Ferrari, with the engine and modern technology of a Tesla. It perfectly blends aesthetics and function."


- Reagan Cook, Vaer Co-Founder

Vaer watch D4 black lume

II) Value Proposition

The D4 is powered by the Japanese VS-22 which is unrivaled in terms of performance in the segment. While there are other watches with these movements in the same price-point as the D4, very few offer USA assembly, and none also offer such strong water resistance capabilities or guarantees.

In addition to it’s impressive water-resistance and top-performing movement the D4 boasts one of the best executed stainless steel cases available for under $1000 (customer & press comparisons consistently praise the D4's case execution). The 38mm case boasts attractive curvature and refined finishing details through-out including highlight chamfering on the lugs and bezel. Like all Vaer watches the D4 uses an AR-coated scratch-resistant sapphire crystal to protect the dial, and as an automatic, also boasts an AR-coated sapphire crystal exhibition case-back.

To further enhance the functionality and value of the watch, every D4 comes standard with two interchangeable 20mm straps. Our standard D4 strap is a comfortable and waterproof FKM rubber quick-release tropic strap, and it’s complemented by a range of secondary strap options from our USA-Made Horween leather strap, our premium stainless steel bracelet, and several rugged and affordable nylon options.

III) Care and Handling

The Vaer D4 is a durable, dependable and highly accurate solar watch designed to last for decades with proper care. We’ve written this guide to explain the basics of the watch, and how to maximize its longevity.

Vaer watch D4 front and back

How do I charge my Solar Watch?

Solar watches recharge fastest in natural light. When left in direct sunlight, the watch will reach a full charge in 6 hours (which will then last for 6 months if left in total darkness). However, this type of planned charging is largely unnecessary. If worn daily, the watch will absorb enough ambient light to maintain a charge perpetually. Incandescent, flourescent, LED and even candle light can all be used to power the D4, with the strongest and brightest light sources providing the fastest charge. If left in complete darkness for over 6 months, we recommend leaving the watch in direct sunlight for a few hours to achieve a significant charge prior to resuming daily wear.

How long will this watch last?

One of the biggest advantages of solar-powered watches is their longevity. While they do eventually require replacement batteries, a Solar watch battery will last 2-4 times longer than standard quartz battery, typically between 8 to 10 years. Even though they are perpetually re-charged, the inherent nature of cells means that at some point they will almost certainly suffer from corrosion and degradation. Fortunately, like other quartz watches, the D4’s batteries can be easily replaced at a marginally higher cost than batteries in most other wristwatches - typically between $10 and $20.

Installing Vaer Quick Release Straps

The Vaer D4 watch comes standard with a pre-installed quick release strap. As our most comfortable and adaptable strap, we believe it is a great introduction to our strap lineup. To remove the standard strap, pull in the small metal knob to disengage the springbar. To attach a quick-release strap, position the end of the bar into the notch on the watch lugs and pull in the metal knob on the other end. Align the loose end of the bar into the second notch, and release the tension of the spring to lock the strap into place. Make sure the strap piece with the buckle is attached to the top of the watch case.

Vaer watches single pass strap close-up

Integrating Vaer Single Pass Straps

While this watch ships standard with our easiliy interchangeable quick release straps, it can also be worn with our nylon single pass straps (a design that is sometimes referred to as a NATO strap). Unlike a traditional watch strap, which is made of two pieces and attached to the watch with removable springbars, our nylon single pass straps are made of a single piece that can be removed or installed in seconds. All single pass straps are sold with a glass vial containing heavy duty 20mm springbars, and a stainless steel springbar tool.

Installing the Vaer Single Pass Strap

If you’ve opted to purchase an optional single pass strap with your watch, or already own a 20mm nylon strap, you will need to remove the standard quick release straps and in- stall springbars between the lugs of your watch. Once the bars are in place, simply feed the tail end of the single pass strap through each of the two springbars starting from the top of the watch. Depending on the size of your wrist you may have extra length of nylon extending beyond the last keeper loop. Simply fold back the tag end of the strap through the keeper. To secure the extra length, feed the strap back toward the buckle until it is tightly secured.

Using Your Watch in the Water

This watch is perfectly suited for underwater activity. The caseback and crown use a threaded screw-down design to maintain an airtight seal. We recommend rinsing the straps and watch case in freshwater after ocean use to remove any build-ups of salt. Though our leather is water resistant, we do not recommend submersion in water - switch to your included ocean-ready strap for this type of activity.

IMPORTANT! Do not expose your watch to water or steam if the crown is not secure. Our waterproof warranty does not cover flooding from misuse if the crown is unlocked.

Vaer watches crown detail

Operating the Watch's Movemen

tIn order to set the time on the watch, unscrew the crown counterclock-wise. Once the crown is disengaged from the threading, pull out until you feel a gentle click (Position 1).

Changing the Date

To access Position 2, pull the crown out to the first “click” to access date setting. If your watch has a date window, you can rotate the crown clockwise to change the date. If your watch does not have a date window, this setting can be ignored.

Setting the Time

To access Position 3, pull the crown out to the second “click”. From this position you can rotate the crown clock- wise to change the time. Once the time and date are set, and the watch is properly wound, push the crown in, and screw it back into the locked position.

IMPORTANT! Only advance the date when the time is after 2AM and before 10PM. Advancing the date wheel close to midnight can the damage the movement.

The gasket sealed crown ensures water resistance, and it must be screwed and sealed during water exposure to maintain warranty.

Vaer watches D4 Navy

Additional Resources

Click here to view all product manuals.
Click here to access our company FAQ.

Ryan and Reagan co-founded Vaer Watches in Venice, California in 2016. As small business owners they handle just about every aspect of the daily operations of the company from watch design and supply chain management, to customer support and photography. Over the years, they've learned a thing or two about watchmaking, online retail, and American sourcing and assembly. If you have a question, comment or correction related to this article you can contact the authors directly at team@vaerdesign.com.

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