A Longines watch marked 30 m, 100 m or another depth equivalent is rated for pressure—not guaranteed safe to wear at that literal underwater depth. Longines explains that its metre figures correspond to overpressure applied under ISO 22810. For practical use, check the marking on your specific watch and follow its matching instruction manual.
What the metre rating means
The number is a pressure equivalent, not a promise that the watch can be taken to that depth in ordinary use. Longines’ explainer describes the rating as static pressure rather than usable submersion depth. A 100 m marking therefore does not mean you can safely descend to 100 metres with the watch.
As an Amazon Associate I earn from qualifying purchases.
The cited Longines L896 instruction manual, dated 2025-04-28, lists the following case-back markings and equivalents under ISO 22810:
Free tools Windows power users keep installed
One-click scans. No signup required.
| Case-back marking | Meaning in the L896 manual |
|---|---|
| No marking | Not water-resistant |
| 3 bar | 3 bar overpressure; 30 m equivalent |
| 5 bar | 5 bar overpressure; 50 m equivalent |
| 10 bar | 10 bar overpressure; 100 m equivalent |
| 30 bar | 30 bar overpressure; 300 m equivalent |
This table is from the L896 manual, not a universal specification for every Longines. Read the case-back marking and the instruction manual for your exact watch.
#1 Best Overall
- ⌚ MENS WATCHES ANALOG: Mens military watches made with shock-resistant stainless steel case and anti-scratch mineral window, exquisitely crafted and durable. Men's watch strap width: 22mm / 0.86 inches, stainless steel case: 42mm / 1.65 inches.
- ⌚ MILITARY WATCHES FOR MEN: This mens field watch is very suitable for active lifestyles, with a comfortable double nylon strap, will suitable for personal use and good for anniversary, graduation, business, birthday , the father's day , Christmas .
- ⌚3 ATM WATERPROOF MILITARY WATCHES: 30M waterproof, sweat-proof, rain-proof and hand-washing for daily life, no problem. But NOT suitable for swimming, bathing, diving or touch hot water. Perfect for most of indoor / outdoor sports.
- ⌚ EASY TO READ TIME: 12 / 24 hrs military time and luminous dial. The mens watches equipped with date calendar can tell you the time quickly and accurately. Come with luminous function, easy to read the time even in the dark.
- ⌚ PURCHASE WITHOUT WORRY: Japan imported quartz analog movement and battery, long-term operation. for 1 years,24-hour customer service is at your service.
What activities are safe?
Swimming, showering and snorkeling
Do not infer permission for swimming, showering or snorkeling from a metre figure alone. Longines’ general article discusses rating categories, but activity guidance should come from the manual for your specific model. If that manual does not clearly address your intended use, ask Longines service before exposing the watch to water.
Scuba diving
Longines says a 100 m/10 bar watch is not recommended for scuba diving. Do not treat that rating as a scuba-use guarantee; follow the exact model’s instructions.
Rank #2
- FUNCTIONS: Countdown,Snooze,Hourly time,Date/Week,EL night-light,Stopwatch(1/100 seconds),Alarm,12/24 hour formart
- 164FT/50M WATERPROOF:Can't wear swimming and taking a hot bath. Because the general watch uses a sealing method to prevent the intrusion of sweat and harmful gases, it is not absolutely not water.only wash hands, shower, Satisfy daily use.NOTE: *Please don't press any buttons under water*
- HIGH QUALITY:Made with quality materials which enable the watch to be tough and durable.COMFORTABLE :Silicone watch band,Suitable for your wrist, Light weight and comfortable to wear.
- BACKLIGHT UPGRADE：Easy-to-read numbers can be clearly seen during the day and night.
- GIFT : It is a great gift for family and friends, especially suitable for you.
Prepare the watch before it gets wet
- Before immersion, make sure the crown and any pushers are pushed in or screwed down, as applicable.
- Do not operate the time-setting crown or pushers while the watch is underwater.
- If the watch has been exposed to seawater, rinse it with fresh water.
These precautions are specified in Longines’ instruction manual. The manual also warns that water resistance can be affected by dried gaskets or an accidental impact on the crown.
Water resistance needs checking
Water resistance can change over time, so Longines recommends checking it once a year at an approved Longines Service Centre. Do not open the watch yourself: Longines’ manual says, “In no circumstances should you open your watch yourself.”
For example, the current Longines US listing for the HydroConquest reference L3.782.4.06.6 specifies water resistance up to 30 bar (300 m), a screw-in crown and a screw-down case back. That specification applies to that listing, not the entire Longines range.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Water damage and warranty
Longines’ international warranty covers qualifying material and manufacturing defects, while excluding damage related to improper use, neglect, accidents or failure to follow the instruction manual. Whether a particular water-damage claim is covered depends on the circumstances and warranty terms; consult Longines or an official service centre for a case-specific answer.
Quick Recap
Official Longines references
- Longines instruction manuals (including the cited L896 manual, dated 2025-04-28).
- Longines Australia: Water Resistant Watches—meaning and features.
- Longines US HydroConquest, reference L3.782.4.06.6.
- Longines warranty and authenticity.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
