How Underwater Communication Is Changing: From Hand Signals to Sonar Messages

 

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Diving is one of the few activities where safety rules are based on the assumption from the very beginning that help may not be available. According to professional diver Vytis Vilkas, underwater there is usually no backup call, no connection to the surface, or the ability to quickly transmit information. Therefore, everything – from planning to reaction – must work without external means. This principle remains, but additional means are emerging that allow you to have a backup communication channel even during deep or limited visibility dives.

 

Signals that everyone learns

 

Although diving equipment and training methods have improved over the decades, the main method of communication underwater has remained the same – visual signs. Divers communicate with hand signals, flashes of light, or touches, because neither voice nor communication devices work at depth. This is a universal system that is taught in basic courses and allows you to communicate even when divers speak different languages. The world's largest diving training organization PADI – Professional Association of Diving Instructors – states that the most commonly used hand signals are internationally recognized and allow divers of different languages ​​to communicate underwater without words. Meanwhile, the Recreational Scuba Training Council (RSTC) has approved a standardized set of basic signals, which most training agencies follow.

 

However, this system has its limits, which are determined by the environment itself. In poor visibility, mud or stressful situations, signals can be overlooked or misunderstood. “Hand and light signals are most commonly used, especially when diving in the dark or underground. We usually have no contact with the surface, so when conditions become difficult, signals alone are not enough. For example, if the water is murky, you have to communicate by touch. In such situations, communication becomes difficult – although the signals are simple, they are not always properly understood,” says Vytis Vilkas. Therefore, preparation is of paramount importance for safety: clear agreements before diving, team discipline and trust in the people you are diving with. “The most important thing is experience and preparation. During the courses, everything is explained in detail: checking the equipment, talking before diving, discussing plans and possible problems. The more you talk and plan before diving, the safer the dive and the fewer misunderstandings between team members. In more serious dives, you usually dive with the same team – you know the people, you know what to expect, and this increases safety,” the instructor adds.

 

Technology in everyday diving

 

Although diving often still relies on human preparation and team agreements, technology has long become a part of everyday divers’ equipment – ​​especially where accuracy is required. Divers use computers, decompression planning systems, bottom timers and other devices that help track time, depth or gas consumption. However, none of them is considered the only solution - in professional diving, all equipment is duplicated, and advanced devices always have simpler, more mechanically reliable counterparts.

Although diving often still relies on human preparation and team agreements, technology has long become a part of everyday divers' equipment - especially where precision is required. According to technical diving instructor Vytis Vilkas, the difference between technology and human preparation is clear: "You can have the most advanced computer, but if you yourself do not understand what is happening, it will not help. However, when the brain begins to function poorly due to cold, fatigue or stress, a computer that does not feel emotions and does not succumb to environmental influences becomes more reliable. In such cases, its information can be more logical than a human decision."

 

Current technologies can provide an additional layer of security. “Technology allows divers to see more – depth, time, temperature, and now to stay in touch. This is especially important when visual contact is lost, visibility changes, or the situation develops differently than planned. This option has already been integrated into the Huawei Watch Ultimate 2 smartwatch, in which communication works even underwater,” says Urtė Eidžiūnaitė, Head of Product Training at Huawei in Lithuania.

 

Underwater sonar communication

 

The Huawei Watch Ultimate 2 has become the first smartwatch that allows messages to be transmitted between divers underwater. The communication does not work via radio signals, but via ultrasonic waves, which propagate even under high pressure.

 

The watch allows you to send pre-prepared messages up to 30 meters away, and an SOS signal up to 60 meters away when it is no longer possible to communicate using signs.

 

Unlike traditional diving equipment, this solution does not require additional transmitters or a surface station - the connection is built directly into the watch, which also acts as a full-fledged dive computer. It is resistant to water pressure, which occurs at a depth of 150 meters, records depth, time, decompression data and other readings, and if necessary becomes a backup communication channel where it simply did not exist before. “Most divers do not use complex professional communication equipment. Therefore, it is quite logical that such a function appears precisely in a watch – a device that divers often wear. No additional transmitters or separate equipment are needed here: one device that you already use for diving simply provides another useful opportunity – to transmit a message or SOS signal. Such a solution is suitable not only for experienced divers, but also for beginners or amateurs who want to have a backup communication method without complex equipment. In addition, the watch is also designed for other extreme activities – from climbing to night hikes, therefore it becomes a universal tool for outdoor sports,” says U. Eidžiūnaitė.”

 

The Huawei Watch Ultimate 2 is readily available in the EU with a starting price of approximately €899 / £799.99, but it has limited to no official availability in the USA.

EU Price and Availability

The Huawei Watch Ultimate 2 was launched in Europe in September 2025 and is currently available for purchase through various retailers and the official HUAWEI UK Store and other local European Huawei online stores.

 

    Price: The base model (with a fluoroelastomer band) is generally priced around €899 or £799.99. A version with a titanium band is also available for a higher price.

    Availability: It can be purchased online via national Huawei websites and major retail partners across Europe.

 

USA Price and Availability

Official US availability for the Huawei Watch Ultimate 2 is highly limited or non-existent due to ongoing geopolitical issues.

 

    Availability: Huawei does not have a major retail presence in the United States for its smartwatches, and the Watch Ultimate 2 is not expected to be officially released or supported in the US market.

    Price: There is no official US pricing. If the watch is available through unofficial third-party importers, prices will vary and consumer support/warranty options would be uncertain.