Review: xDeep Black BT OLED bottom timer

source: xDeep

My twitter chums will know I've been after a trimix computer with one of those fancy displays for a long, long, long, ... long, time. Subsequently I never bought one; the reason being I prescribed to a GUE tech 1 class and chose to technical dive with the aid of a simple bottom timer. As a result, all I wanted was a simple bottom timer. That said, not all bottom timers are simple; and some are less simple than others. The xDeep Black BT is one such device; it's a bottom timer ... and then some.



What's included

In the box

  • Bottom timer 
  • Strap 
  • USB connector 
  • USB cable (also acts as charging cable) 


xDeep Black BT

The glass display is housed in a black square of monolithic polyacetal (looks like metal, but it's not); made up of two pieces held together by some attractive metal screws. There are two silver push buttons (one on each side), drilled holes in each corner to facilitate bungee, and 2 slots to allow the use of the enclosed strap. The unit feels surprisingly lighter than expected, but not fragile.

USB connection

Push button controls


xDeep Black BT

The unit looks fantastic. The black finish isn't gloss, but it's not matt either; a sort of brushed effect with 'BLACK' etched into the casing. The glass display reflects nicely, and once lit up, looks great.


  • Depth 
  • Max depth 
  • Average depth - resettable 
  • Time elapsed 
  • Stopwatch - resettable, pause, restart 
  • Clock 
  • Temperature 
  • Compass 
  • Logbook 
  • VSI - Vertical Speed Indicator 
  • Profile graph 
  • Alarms; depth, ascent, time, clock 
  • Battery level (in %) 
  • Rechargeable via USB 

Navigating the menus

I decided not to read the instructions and see how intuitive the timer was. Well, that's my excuse; In all honesty I was too lazy, but it was a good test nonetheless. The basic sequence is 'short press / long press' of the generous buttons that protrude slightly from the bottom of the display. The internet tells me that early VR computers used this system and it upset users greatly, but I found the xDeep Black BT easy enough to use. I was able to find everything I needed; and I'm a simpleton.

I quickly sussed how to access a demo dive, so I could establish how the compass worked, along with how to reset the stopwatch and average depth.

Main Menu

Settings Menu

Demo Mode

It was soon clear the xDeep Black BT is very customisable. You can choose any colour imaginable for whichever reading you like, or choose from the preset "themes."

"Pink Theme"

"Desert Theme"


The most important test was obviously how the unit dived. I opted for the bungee mount; the included strap was atrocious. The unit is lovely and neat, and quickly settled on my right forearm between the crook of my elbow and the dry ring system. I was initially concerned the folds of my drysuit would press the buttons, but no matter what way I bent my arm the timer remained in timer mode.

In water the timer came to life almost immediately. By 20m I was in the dull familiar surroundings of the lough, with 2-3m of muddy visibility. The timer was like a lighthouse; especially compared to my LCD mares puck. No more shining my dive light at funny angle in a vain attempt to read the display without washing it out.

Oled and led displays are common among the new breed of computers, and the OLED display of the xDeep Black BT is definitely a contender. My buddy was diving an OSTC and neither of us could see any real difference. Wifebuddy has a Liquivision Xen, and the xDeep Black BT is very similar. The viewing angle on the xDeep Black BT isn't as good as the OSTC or Liquivison Xen, but the timer was almost turned away from me when the display disappeared.

The display is logically laid out; a quick look at the timer supplied the critical information I needed during the dive. At the deco stop I played about with the resettable stop watch, and it worked a treat; two go's and I was able to speedily reset and return to the main screen.


I imagined the compass to be more of a gimmick, but to be honest, it was very good. I checked it against my tried and tested suunto sk7, and the bearings where identical. The compass display is also very clear; depth and dive time were still displayed along the top of the screen. It is also possible to pre program bearings to allow a route to be followed during the dive, and a return path is generated automatically. Very clever, but I'm not sure I could be bothered.

The VSI (Vertical Speed Indicator) is a bar that runs up the left hand side of the screen monitoring a divers ascent rate, and can be customised to monitor varying ascent rates at different depth ranges. It was accurate, but I didn't pay a lot of attention to it once I'd noted it's function.


Post dive, everything is there on one screen. It is logically displayed and has everything you could want to complete your log book.

PC connection

Thankfully the xDeep Black BT package contains a USB cable, that not only charges the unit, but also acts as a data cable allowing the logbook to be exported in .UDDF format. xDeep Black BT also informed me that any USB plug can be used as a charger if the voltage is correct; including phone charger plugs - but do check the voltage!

USB adapter clicks into place

USB cables plugs into adapter

Once connected via USB to the computer, the USB must be activated on the xDeep Black BT, then the computer will recognise it as a mass storage device. Amazingly it worked first go and was chatting away to my imac instantly. Simple instructions on the xDeep website also alllowed me to quickly register the unit and complete a firmware update.

"Start" USB for computer to recognise unit

"Stop" USB before disconnecting

iMac display once connected


For £219 the xDeep Black BT is a bargain. The features are fantastic and the display is excellent - what else do you need from a bottom timer? I found the buttons easy to use and the menu system easy to navigate. The built in bungee mount works perfectly, i strongly recommend throwing away the strap; it's very, very bad.

The xDeep Black BT is definitely a valid contender to the Liquivision Xen; a question that most divers are pondering. The Xen has a bigger price tag at a £389, offers similar options, but lacks the compass. Is the xDeep Black BT as good? Better? It's a tough question. The only thing about the Xen is it feels weightier in the hand, and exudes pure luxury. It's kinda like comparing an iphone to other smart phones; they all do the same job, some phones offer more, but the iphone just 'feels' better. I suspect the Xen will survive the new rival.

Xen vs. Black BT

Bang for your buck; the xDeep Black BT is fantastic value for money, and it will win over divers wanting an OLED back up timer to their trimix computer, or those on a budget. The 'bottom timer only' divers may decide differently, but you would need to dive each unit independently to appreciate the subtle advantages of the Xen.

A word of warning though - I put a few scratches on the screen almost instantly; and I haven't a clue how. If you buy an xDeep Black BT; put a screen guard sticker on ASAP.

I like it!

PROS: OLED, rechargeable via USB, PC connection included, excellent value, upgradable to trimix computer.

CONS: viewing angle not as good as other OLED gauges, screen easily scratched, rubbish strap.

Safe diving folks!


  1. Great review Andy! The xDeep is definitely very cool - looking forward to getting one myself soon :-)

  2. Does it show ascent rate in meters per minute? I've been wanting one of these with ages. Thanks. Dec

  3. Yes Dec; ascent rate is in m/min.

  4. Isn't the case Delrin rather than metal?

  5. It's made from monolithic polyacetal (POM); looks like metal!

    Thanks for pointing that out though, I'll update. ;)

  6. Great review - and I think the picture at the end just makes it.

  7. One of the first, if not the first, review of this BT. Great work!
    Isn't Delrin a commercial name for monolithic polyacetal?

  8. Damn you. Now the Want will be convincing me that I need one of these.

  9. @Marce - possibly, but I wasn't sure! :)

    @Kim - Oh yeah, you must feed The Want ... NOW!!!!

  10. But ... I only just fed it a shiny new 2x12l set and bladder. On the other hand, I already checked where I can buy one of these where I live so things are looking grim for my wallet.

  11. I'm sorry Kim, but The Want is ALWAYS HUNGRY!!!!! :D

  12. So, given the choice. Which one would you buy?

  13. Money no object Colin? I'd go Xen.

  14. Hy, what about the scratches on the screen ? I thougt the material is saphir glass or any tempered glass ? Isn't it ?

  15. I emailed xdeep and they responded:

    "The glass is made of the polycarbonate with a special abrasing resistant
    coating. It's almost the same resistant as regular glass."

    About as much as i can tell you. The glass can be replaced though.

  16. Really nice review - it answered my questions and then some! Now if only I could find a diveshop that actually had it in stock...

  17. Yeah, they're not the easiest thing to source are they?! Lol!

  18. Now you've been using it for a year, any chance of an update, do you still have it and has it survived weekly trips to Ringhaddy!

  19. After a year of diving my xdeep or Genz Black (how they call it right now) had issues with the pressure sensor. Waiting over three weeks now and no response from them to me or the shop where I bought it. Very bad after sales!


Thanks for commenting, I appreciate it!

Safe diving buddy.