Bühlmann Decompression Dive Watch
The «Mother» of all Dive Watches
Technical Data
The Watch
Water-resistant to 57.5 ATM for the 01-Edition, respectively 35 ATM for the 02-Edition.
On the Bühlmann Decompression 01 a helium valve and professional dive watch features are included. The minute hands is the design highlight because it measures actual dive time (ADT) and decompression security stops time which are shown on the outside and inner turning bezels. These values have to be easy to read.
The case has a 5 degree inclination to facilitate the dial readability.
A 360° view of the Bühlmann Decompression 01 Small Seconds «Druckkammer».
The Bühlmann Decompression Bezel
Unidirectional – clockwise turning – security stops 0-700 ASL bezel for 20m, 30m and 40m dives at the corresponding bottom times. Incorporating the Bühlmann decompression algorithm. The watch comes with the 40m bezel included. The exchangeable 20m and 30m bezels will be available for purchase in April 2022.
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The Bezel Push Lock-Open System
Bezel 01:
Press the bezel down to unlock or lock the screw-in crowns and the screw-in helium valve.
Bezel 02:
Push and turn the bezel to unlock or lock the crowns
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See the Bezel Push Lock-Open System in action
The Fly-no Fly Indicator
The Divers Alert Network (DAN) recommends a 12-hour minimum surface interval before flying, and the Professional Association of Diving Instructors’ (PADI) “flying after diving” guidelines say divers should not ascend to a high altitude within 12 hours of completing a single dive or 18 hours after doing multiple dives. The Fly-no fly indicator allows you to determine when it’s safe to fly.
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The Flexible Lugs Joint
The Divers Alert Network (DAN) recommends a 12-hour minimum The flexible lugs joint on the 12 o’clock lugs ensures snug fit for every wrist size.
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Dive View
Bezel 01:
X1 grade Superluminova ® on minute hand, hours disk, small seconds hand, indexes, inner bezel ADT triangle marker and outer bezel security stops circular marker.
Bezel 02:
X1 grade Superluminova ® on indexes, minute hand, hours disk, inner bezel ADT triangle marker and outer bezel security stops circular marker
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Specifications 01 – 3 Crowns
Type of Production
Swiss made
In-house production
Case size
46 mm diameter
Case Features
Stainless Steel 316L (1.4435 grade with higher chromium and nickel content for enhanced corrosion resistance and resistance to saline water)
Sapphire crystal with anti-reflective treatment
Screwed case-back with 8 screws
Uni-directional (clock-wise) Decompression security stops bezel
Push lock-unlock bezel for the screw-in crowns and the screw-in helium valve
5 degrees case inclination
Flexible strap joints on the 12 o’clock strap lugs for snug fit on all wrist sizes
Finish
Polished central case-body. Brushed lower case-body with polished bevels. 6-12 brushed lugs. Circular brushed and polished engraved bezel
Dial
Various colors dial with different 15min. segment on the inner ADT (Actual Diving Time) turning bezel.
Luminous X1 Grade Superluminova ® luminous minutes hand, hour disk, indexes, bezel and inner turning bezel markers
Strap
Black perforated rubber strap with stainless steel pin buckle
Strap width
19.2mm
Water Resistance
57.5 ATM = 575m = 1866ft
(The Bühlmann depth record)
Specifications 02 – 2 Crowns
Type of Production
Swiss made
In-house production
Case size
46mm diameter
Case Features
Stainless Steel 316L (1.4435 grade with higher chromium and nickel content for enhanced corrosion resistance and resistance to saline water)
Sapphire crystal with anti-reflective treatment
Screwed case-back with 8 screws
Uni-directional (clock-wise) Decompression security stops bezel
Push lock-unlock bezel for the screw-in crowns
5 degrees case inclination
Flexible strap joints on the 12 o’clock strap lugs for snug fit on all wrist sizes
Finish
Polished central case-body. Brushed lower case-body with polished bevels. 6-12 brushed lugs. Circular brushed and polished engraved bezel
Dial
Various colors dial with different 15min segment on the inner ADT (Actual Dive Time) turning bezel.
Luminous X1 grade Superluminova ®, minutes hand, hour disk, indexes, bezel and inner turning bezel marker
Strap
Black perforated rubber strap with stainless steel pin buckle
Strap width
19.2mm
Water Resistance
35 ATM = 350m = 1150ft
Technical data in action
Disclaimer
Diving can be dangerous for your health if safety rules are not followed rigorously. Do not dive before you have concluded adequate training courses with a certificate from an approved diving organization.
Bühlmann Decompression watches do not replace decompression tables or dive computers to plan and control your dive.
Dive computers and decompression tables provide correct data for security stops with regard to a higher variety of dives and with respect to depth, bottom time, non-repetitive and repetitive dives, sea level or above sea level altitudes. Dive computers calculate security stops based on your real dive profile, dive history and personal data.
The Bühlmann Decompression watches show only educational and decorative information with respect to security stops. Results from decompression tables or dive computers must always prevail.
Before you dive
Adapt the watch strap to your diving suit
If you have bought a long strap for your Bühlmann Decompression watch from Watch Angels install it and – if necessary – cut it to the appropriate length.
Mount the correct bezel on your watch
At Watch Angel’s you can buy three different bezels, one for 20 meters depth, one for 30 meters and one for 40 meters depth. When you plan your next dive chose the correct bezel for your bottom line and mount it correctly on your watch.
Example: You want to go to 30 meters deep. Chose the 30 meters bezel and install it on your watch.
Change your Fly / No Fly indicator to green using the crown at 12 o’clock
On your Bühlmann Decompressor watch you have an indicator at 9 o’clock to change manually your dive status by using the crown at 12 o’clock. The respective values must always come from your dive computer. Red means you shouldn’t dive. Green means you are free to dive. These values are especially important for repetitive diving. Turn the main crown to change the indicator’s color.
Example: If your computer tells you that you shouldn’t dive in the next 4 hours, change the indicator to red, after 4 hours you can change it to green again.
Decompress the helium pressure of your watch
At 11 o’clock on your watch you find a helium pressure valve. When diving with a helium/oxygen or similar gas mix, the extremely tiny helium atoms might intrude your watch and create there a hyperpression. Opening the crown of the helium valve this gas pressure is decompressing. Screw your crown down carefully as soon as all additional gas pressure is levelled out.
Control your dive time
At the help of the crown at 1 o’clock (with colored cap) you can control your dive time with the watch’s inner bezel. Turn the crown (two directions possible) until the triangle on the inner bezel meets your minute hand. As your dive plan on your dive computer or your decompression tables already tell you all the necessary steps and security stops, you can include them in your dive plan too. The minute hand will tell you how many minutes you have already been diving.
You can also use the values for security stops on your bezel. They include large security margins on all parameters of your dive profile.
Example: Dive starts at 12:08. Depth (bottom line) is planned at 30 meters; time is 75 minutes (see example on your 30 meters bezel). Turn the triangle on the inner bezel to the minute hand. When your minute hand reaches 08 plus 5 minutes descent and 75 minutes bottom time you already have a total of 88 minutes (1 hour and 28 minutes). The minute hand will then stay at one hour and 8 + 28, i.e. 36 minutes. You should start your ascent.
You already can see that your dive trip exceeds a normal dive. Or you shorten your dive a lot or you will have to prepare additional air reserves on your way.
Close all the crowns
Bevor you start diving it is essential that you screw down the three valves at 11, 12 and 1 o’clock! If you forget, water might enter the watch. And, as you certainly know, especially salt water can ruin the movement of your watch in a short time.
While you dive
Control your ascent
When turning back to the surface from your planned bottom line (maximum depth) decompression starts in your body. The decompression process needs time. The maximum speed for ascent is 10 meters per minute, in the last ascent phase (10-0 meters) you should lower it to 6 meters per minute. On the small second at 3 o’clock you can control your ascent rate. It shouldn’t be higher than one minute for 10 meters (or 6 seconds for one meter).
Example you start your ascent at 30 meters. Don’t take less than 2 minutes to reach a depth of 10 meters.
Security stops
On your dive computer or on your dive tables you see the necessary decompression/security stops for your dive. The watch’s outer bezels show you examples of the needed security stops for the indicated depth and the planned bottom time.
Most probably the values on the bezel will be quite higher than the values calculated by your dive computer or coming from your decompression tables. The reason for this is simple: On the bezel we show the maximum values for a long bottom time and the highest class of repetitive dives. Repetitive dives bring along longer decompression times. So, if you follow the values on the bezel for the indicated dive trip you can be sure that you will not have decompression problems.
Let’s take your bezel 30 meters as an example. It shows the following values:
0-700 m ASL: This reference confirms that you are using security/decompression values for 0 to 700 meters Above Sea Level. If you dive at higher altitudes, for example in the mountains, the security stops will become longer.
Bottom time: 75 minutes. This value is much higher than a normal recreational dive time for 30 meters depth.
Repetitive dive class: L. This value indicates that you use maximum security values for several consecutive dives. Repetitive dives cause an additional security margin.
On the outside bezel you find the security stop’s depth in the outer range and the security stop’s minutes on the inner range:
First stop is for 7 minutes at 9 meters. Turn the mark for the first stop to the position of your minute hand and you will see the round white dot 7 minutes ahead. You can turn your bezel only clockwise to avoid any risk to shorten your security stop time by a wrong manipulation. After 7 minutes the minute hand will equal the white dot and you can go on to the next security stop.
Second security stop will be for 15 minutes at 6 meters deep. You can turn the bezel clockwise to the new position of your minute hand. The procedure is the same as for the first security stop.
The same applies for the third security stop of 42 minutes 3 meters. This stop is extremely long due to the depth of 30 meters and the long bottom time of 75 minutes.
You can now plan the duration of your complete dive: We already had 88 minutes before ascending. Now we add 4 minutes for the ascent and 7, 15 and 42 minutes for the security stops. Total of your dive trip will be 156 minutes, i.e 2 hours and 36 minutes. This is clearly to long for recreational diving. It’s better plan a much shorter and less risky dive.
After your dive
Open the crown at 1 o’clock and turn the inner bezel to 12 o’clock
Turn your outer bezel clockwise to 12 o’clock.
Open your crown at 12 o’clock and put your dive/no dive indicator to red. Remember that you should not travel by plane for at least 24 hours after your last dive.
Screw down carefully all your crowns to grant water resistance of your watch.