Suunto Eon Steel Black - In Water Review

Suunto Eon Steel Black - In Water Review

The Suunto EON Steel Black is the first Suunto dive computer equipped with two dive algorithms; Suunto Fused™ RGBM 2 and Bühlmann 16 with Gradient Factors.

You can choose the best dive algorithm for your dive and match your profile more closely with your dive team members. The Suunto EON Steel Black is a fully customizable dive computer designed to meet the needs of even the most demanding diver. By wireless connectivity to the Suunto app you can relive and analyse your diving adventure with a mobile dive logbook!

Check out our in water test below!



The EON Steel Black has a robust, durable construction that includes a stylish brushed stainless steel bezel. It has a high-contrast large colour screen that is easy to read even in low light conditions, multi-gas support and long-lasting rechargeable battery. It provides up to 40 hours of dive time with one charge that will last even in the coldest waters. 

The Suunto EON Steel Black supports multiple diving modes: Gauge/Air/Nitrox/Trimix/CCR (fixed point) and includes multiple gas support. It comes with guaranteed water resistance up to 150 metres. Intuitive menus and a simple 3-button layout make it very easy to use despite the many dive options available. Select exactly the dive details you want to see on the screen, and in which view style they are shown. 

The Suunto EON Steel Black now comes in a hard re-usable storage case and with user-updatable software (with Suunto Link). It has been designed, built and tested in the toughest diving conditions and carefully hand-built in Finland by Suunto’s internal dive team. It comes with 2 strap options – traditional or bungee in either black or lime.


The Suunto EON Steel Black is compatible with the Suunto App and lets you easily transfer all dive data over Bluetooth to your mobile. In the Suunto App you can share your diving adventures and build an all-inclusive dive history by enriching your dive logs with photos, comments and location. Review and analyse your dive data including time, maximum depth, device settings and gas consumption (when using a Suunto Tank POD).

With the addition of the tank POD, you can follow your tank pressure, gas consumption and remaining airtime straight from your wrist. It can connect with up to 20 PODs!


The new Suunto Fused™ RGBM 2 dive algorithm – developed with Dr. Bruce Wienke's RGBM (Reduced Gradient Bubble Model) -provides better possibilities for deep air and repetitive diving. It has rebreather capability and supports dives down to 150 metres. It allows shorter ascent times on deep air dives and on repetitive dives. On repetitive dives, the change primarily affects Air/Nitrox dives.

In addition, the Suunto Fused™ RGBM 2 doesn’t require your body to be completely free of residual gases when calculating no-fly times for a normal airline pressurized up to 3000 meters. The change reduces the required time between your last dive and flying while maintaining your safety.

The Bühlmann 16 GF algorithm tissue calculation model was developed by Swiss physician Albert A Bühlmann, M.D. The Bühlmann decompression algorithm is a theoretical mathematical model describing the way in which inert gases enter and leave the human body as the ambient pressure changes. Suunto’s Bühlmann 16 GF dive algorithm assumes perfusion limited gas exchange and multiple parallel tissue compartments and uses an inverse exponential model for on-gassing and off-gassing, both of which are assumed to occur in the dissolved phase (without bubble formation).

GFs (Gradient Factors) are a way to add conservatism to the Bühlmann algorithm by adding deep stops to the dive. They are divided into two separate parameters - Gradient Factor Low and Gradient Factor High. By using GF with the Bühlmann algorithm you can set your safety margin for the dive by adding conservatism to control when different tissue compartments reach their acceptable M‑value. (An M-Value is the maximum value of absolute inert gas pressure that a tissue compartment can take without presenting symptoms of decompression sickness). Gradient factors are always defined as percentages. The Low % value determines the first deep stop, while the High % value defines the allowed M-value once surfacing. Using this method, the GF changes throughout the ascent.

The default setting of Suunto's Bühlmann 16 GF dive algorithm is 30/70 which means that the first stop would take place once the leading tissue reaches 30% of its M-value. The lower the first number is, the less supersaturation is allowed. As a result, the first stop is required when you are deeper. When the ascent continues, the GF moves from 30% to 70%. GF 70 indicates the amount of supersaturation allowed when you get to the surface. The higher the GF High % value is, the shorter the total dive time is, and the less time the diver spends in shallow water. If GF High % is set to a lower value, the diver spends more time in shallow water and total dive time gets longer.

The Suunto Eon Steel Black gives divers the option to choose from continuous or stepped ascent mode in both algorithms – Suunto is the only dive computer manufacturer that gives continuous ascent mode for Bühlmann. It gives you the freedom to customize ascent profile regardless of dive algorithm.  For more information about Suunto Dive Gradient Factors see the video by ambassador Jill Heinerth here.