Submersible Pressure Gauges (SPGs)

Available in three sizes: 2.5-inch diameter with 2-inch face, 2.0-inch diameter with 1.75-inch face, and 1.75-inch diameter with 1.5-inch face. The two larger SPG's feature a tempered glass face and the thin SPG has a scratch and impact resistant polycarbonate face. Just add the HP hose (see below) in your choice of length along with a spool to make the custom SPG configurations preferred by experienced divers. Naked SPGs now include the Spool to mate the hose swivel to the gauge. Our spool also includes the two oxygen compatible O-rings. Note these popular gauges are sold under a variety of brand names such as Dive Rite and Highland, but are all manufactured by Termo in Italy.

Please be aware that if you shake the compact naked 1.5-inch face gauge, you will hear the sound of the internal spring contacting the body because it will not be muffled by the boot. The click sound is perfectly normal for all the 1.5-inch face gauges regardless of brand and in no way affects the performance of the gauge. The larger naked gauges, because they have a larger body do not make this sound.

The 1-inch face is larger than most and relatively easy to read, but for any mini-SPG the indicator needle can be difficult to read underwater. Still, the mini-SPG works well for some applications with the benefit of no hose clutter. The mini-SPG is suitable for use with pony, inflation, and bailout bottles where you just need an indication to the nearest 1000 psi of "full," "partial," or "empty".

SPG Floods

An SPG with water inside is rare and may just mean the SPG was defective, particularly if it is new. If an SPG that has been working is still working when flooded then most likely something broke the seal on the face, usually an impact. Impact damage is an unavoidable fact, particularly with naked SPG's and mini-SPG's used on stage, deco and bailout bottles. It's not serious, just replace the SPG. It's more of a concern to discover a non-working flooded SPG on a cylinder other than the primary. If the SPG is not working then the Bourdon tube might have ruptured and that is often because water entered the tube through a flooded first stage. Diving with stage, deco and bailout cylinders turned off is a common practice to prevent gas loss but the regulator must be charged with pressure before descending or it will flood. If the first stage floods, it should be serviced immediately.

Sometimes divers forget to charge, but in our experience the gas pressure was inadvertently drained before reaching depth. The second stage might accidently be purged while gearing up. Sometimes it purges from the force of entry and free flows until drained or just dribbles out during the descent, which was one of the original reasons for leaving the valve off. If practical, make a habit of charging the regulator again during descent. An alternative on emergency bottles is to leave the valve open but place an inline slide cutoff between the hose and the second stage with an OPV on the first stage.

Miflex XTREME Diving Hoses

The Miflex XTREME high performance range of diving hoses are receiving a great deal of interest from experienced sport and technical divers. A team of Miflex engineers analysed the weak points of traditional diving hoses and developed the XTREME high performance range in cooperation with expert divers for superior in-depth performance. XTREME hoses feature an external nylon safety braiding designed to resist the snags and abrasions that divers can often encounter. Unlike traditional hoses, the XTREME nylon safety braiding is not simply pushed over the hose fittings. Instead the braiding is tightly bound and fixed to the hose core by stainless steel or brass sleeves. The result is performance and durability in extreme situations. All Miflex Hoses are factory cleaned and tested for oxygen service.

Choosing the Best Primary SPG Hose Length

For most recreational divers, the common high-pressure hose length of 32 inches is long enough to be run under the left arm, across the chest and clipped off on the right shoulder D-ring. A few divers with a large chest, or who like to hold their instruments well out from their body when reading, require a longer hose length of 42 inches. Recently, some recreational divers seeking very streamlined configurations are routing their HP-hose with a compact SPG over their left shoulder in the same manner they route their BC hose and those divers are using HP-hose lengths as short as 24 inches and even 21 inches.

Technical divers almost always carry a standalone SPG clipped off to the left waist D-ring. For use with double cylinder configurations, the typical HP-hose length is 24 inches although some divers find that length slightly too short. It's almost always too short when used with a single cylinder configuration. Many divers clipping to their waist D-ring find a HP-hose length of 26 inches to work well with both singles and doubles. Cave and wreck divers also remove the SPG boot for the same reason they remove the cylinder boot, because the boot surfaces have been known to ratchet divers into tight spots making extraction difficult.