TESTCENTRE
Now with air integration
Tern TX
COMPANY : SHEARWATER PRICE : £ 740 WEB : WWW . SHEARWATER . COM
Just like its Peregrine TX stablemate , Shearwater Research ’ s wristwatchstyle computer , the Tern , has also been the recipient of an airintegration upgrade .
The Tern TX has the same full-colour , high contrast AMOLED display as the original , and two other key features remain unchanged from the previous incarnation – the toughened glass window and the rechargeable Li-ion battery . Charging is by way of a supplied wireless station , with a battery life of up to 20 hours .
The 120m-rated Tern is squarely aimed at the sport and advanced sport diver . It ’ s a well-specified instrument with Air , Nitrox , 3 Gas Nitrox , Gauge and Freediving modes . Despite its compact ( 50mm diameter by 16mm thick ) size it has an excellent , easyto-read 3.3cm display .
Bühlmann ’ s ZHL-16C ( with gradient factors ) algorithm provides the Tern with full decompression support and the computer features customisable visual and vibrating alerts . Located on the body behind an attractive black 316 stainless steel bezel , a quartet of buttons access the computer ’ s setup menu and operation during the dive .
Clockwise from top left we have : LiGHT button ( for brightness levels / moving UP menus ), FUNC button ( menu shortcuts
& selection ), INFO ( cycles through screens / returns to previous ) and MENU ( brings up menus / moves DOWN menus ). It ’ s all very intuitive and straight from the box I ’ d expect the majority of adults ( and probably 100 % of primary schoolkids ) to get to grips with it in no time at all . Default setup display is divided into three sections . The upper shows a battery indicator , current depth , gas mode and ascent rate . The middle section No Deco Limit ( NDL ) and maximum depth . Dive time , active gas and alert Indicator sit on the lower rung . There are also two different screen layouts available in each dive mode : Big and Standard , with the
" The Tern TX is a dive-specific instrument "
former consisting of three rows , the latter four , with customisation available in both . During decompression diving , the NDL ( no decompression limit ) is replaced by a red highlighted DECO symbol and shows the relevant depth and time required .
Supplementary screens , accessed indive , provide additional information such as temperature , CNS level , time of day and the like . The Tern TX ' s main point of sale is obviously the ability to provide wireless gas monitoring via Shearwater ’ s Swift transmitter . This compact device simply screws directly into the HP port on the first stage just as you ’ d do with a conventional SPG .
Paring the Swift is as simple as activating AI ( Air Integration ) Mode on the TX then entering its unique serial number , which is retained within the Tern ’ s memory for future use . Up to four transmitters can be monitored by the computer . The second major upgrade from the original Tern is the bonus of a digital compass . Once activated it may be viewed in any of three ways on the display : as an info screen , a pop-up or an overlay , each of which have their advantages .
The Tern TX is a dive-specific instrument as opposed to an all-singing / all dancing multi-sport device and that ’ s exactly where its strength lies . It ’ s very easy to set-up and operate with a display that is clear , concise and easy to read . If your eyesight ’ s not quite what it used to be then the BIG display option is a boon . Switch over to watch mode and you can also wear it as an everyday timepiece .
In my review of the larger Peregrine TX ( Test Centre October 2024 ) I ’ d taken the opportunity to dive both computers sideby-side . At the time I expressed a leaning towards the Peregrine , however after a few more dives with the diminutive Tern TX I ’ m not quite so sure ....
SCUBA SAYS
From absolute beginner through to advanced recreational diver , Shearwater ’ s Tern TX offers multiple dive modes , a digital compass and air integration in a compact , fullcolour and easy-to-read display in a wristwatch-sized package .
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