Dive tools on your HUAWEI WATCH Ultimate Series

NDL calculator

The Calculate NDL tool helps quickly calculate the maximum time you can spend at a given depth in recreational dive without having to take any decompression stops when surfacing. After calculation, the tool outputs an NDL list corresponding to depths of 12–60 m. You can also quickly find results based on the planned depth of your dive.

NDL calculation is affected by the following parameters:

• GF (for recreational dives)
• Gas concentration
• Depth (required when you query the NDL for a given depth)
• Start dive
• Body nitrogen load (automatically stored on the watch)

1. Touch Calculate NDL, swipe up or down on the screen to select Gas, and touch Next.
2. Swipe up or down on the screen to find and select Start dive, and touch OK. You can view the respective NDL for different depths.

   Touch Check precision, select Dive depth, and view the NDL for the chosen depth.

Deco calculator

The Calculate decompression tool estimates the total gases required, and the depths and durations of decompression stops, for a technical dive. It makes it easy to plan your dives and adjust any relevant parameters.

Decompression calculation is affected by the following parameters:

• GF, partial pressure, and bottom depth (for technical dives)
• Gas concentration and gas consumption (When calculating decompression, the tool automatically distributes gases and marks inappropriate gases.)
• Depth
• Start dive
• Body nitrogen and helium loads (automatically stored on the watch)

Apnea training

Free diving is a challenging workout which requires you to undertake apnea training. Normally, you can practice on land by breathing in and holding your breath several times. You can choose different training durations based on your specific ability and your goals. Please follow the advice of a professional instructor when deciding on your training routine.

Before using this feature, pay attention to the following:

• Do not do apnea training if you have hypertension, heart or lung disease, or other diseases or physical conditions which make this type of training unsuitable for you.
• Make sure to carefully follow a qualified instructor's training advice.
• Do apnea training on a soft cushion or bed, and with a professional instructor guiding you.

Apnea test

Before using this feature, pay attention to the following:

• Do not do apnea test if you have hypertension, heart or lung disease, or other diseases or physical conditions which make this type of test unsuitable for you.
• Do apnea test on a soft cushion or bed, and with a professional instructor guiding you.

The test is predominantly used to test and record the maximum length of time that you can hold your breath for, and the diaphragm contraction. Each apnea test consists of four phases:

1. Relax: Before you hold your breath, you should relax physically and mentally in order to conserve oxygen. Perform diaphragmatic breathing during this phase.
2. Take a full breath: Take a deep and slow breath to let your lungs absorb as much air as possible.
3. Start to hold your breath: At the beginning, you'll feel pleasant and peaceful. Gradually, as carbon dioxide builds up in your body, you'll want to breathe. At this point, your diaphragm will start to contract until you are no longer able to hold your breath.
4. Recover your breathing: Relax and exhale naturally, then take a deep and quick breath, and hold the air in your body for two seconds. Repeat this process at least three times. Make sure to recover your breathing every time that you hold your breath.