Regulator Mouthpiece Orifice Sizes

Generally there are four common 2nd stage regulator mouthpiece sizes:

Standard size orifice regulator mouthpiece
- size 1-1/8 inch x 1/2 inch (28.6 mm x 12.7 mm)
Fits: Apollo; Aqua Lung older metal regulators, Conshelf 7 through 21 – snug; Atomic manufactured pre 2005 only and newer T3; Beuchat Evolution, Iceberg and Nitrox, VXT8, VXT Octo, VX4, VX8; Cressi-Sub Ellipse is a 2, XS Compact is snug; Dacor after 1992; IST except Proline is an intermediate; Ocean Master; Pro Sub Avalon; Scubapro S600, S360, S560, R095 and all models before the A700; SEAC; Sherwood most early models – Brut, Shadow, MagnumII, pre 1992 Blizzard + Oasis; Spare Air; Subgear R series and Cayman; Tabata/Tusa not TUSA Imprix.

Intermediate size orifice regulator mouthpiece
- size 1-3/16 inch x 5/8 inch (30.2 mm x 15.9 mm)
Fits: Aeris; Aqua Lung newer, including Titan, Legend, Kronos and Mikron; Atomic pre 2005 use a Standard, newer, larger orifice an Intermediate, if not sure, measure or try on; Beuchat VS3, VS4, VS8, VX10; Dacor Viper + Eagle; Dive Rite including O2ptima rebreather, but not the Jet Stream 4500; Edge HOG + EPIC; Forte; Genesis; Halcyon Rebreather + Regulators; Hollis except 500SE is a Large; Mares (not MARES MR-12-II, III, IV or V); Ocean Edge; Ocean Reef; Oceanic cannot fit Alpha 9 or Omega 3; Odyssey; Scuba Max; Scubapro models after 2010, including A700, C series, G260, R195 and S620TI; Sea Elite; Sherwood Maximus, 1992 and newer Blizzard + Oasis, SR1; SPORASUB; SUBGEAR SG50, SG30, SG10, Aruba and Bonaire, Tigullio, Tilos; XS SCUBA (previously IDI, Osprey is a standard).

Large size orifice regulator mouthpiece
- size 1-5/16 inch x 11/16 inch (33.3 mm x 17.5 mm)
Fits: Apeks; Dive Perfect; Hollis 500SE; and Zeagle 2nd stage regulators. Plus many rebreathers, including Golem Shrimp BOV; Hollis Prism+Explorer; ISC Megladon; Kiss Gem; Poseidon (snug fit); and Titan.

Extra Large size orifice regulator mouthpiece
- size 1-7/16 inch x 13/16 inch (36.5 mm x 20.6 mm)
Fits: Poseidon regulators.

Tech Tip: Inspect Your Regulator Mouthpiece

When is the last time you gave any thought to your regulator mouthpiece? Our service technicians tell us one of the most commonly damaged parts they discover during routine maintenance on a regulator second stage is the mouthpiece itself.

Many divers bite down much too hard on the mouthpiece, particularly if it is a poor fit. Besides the fact that biting too hard may cause the diver to climb out the water with an annoying headache, we even find bite tabs completely missing from the mouthpiece where they have been literally 'chewed off'. If that's happening to you, consider trying a different style of mouthpiece.

A more subtle damage often responsible for second stages 'breathing wet' is an almost invisible tear in the mouthpiece, just past the mounting lip on the second stage body near or under the cable tie. These often can't be seen unless you stretch the mouthpiece by hand and inspect in bright light.

Inner Corsair Wall

Wall Dive | Boat access

Depth: 10 m (33 ft) to 60 m (197 ft)

Inner Corsair Wall is a very spectacular wall dive with lots of ledges, caves and drop-offs. The top of the wall starts at 10 metres and bottoms out at over 60 metres.

The wall is a good cray spot and good crays have been caught at 38 metres. Inner Corsair Wall can only be dived on slack water as it is only just out of the heads. Although shipping does not normally transit this area, it's technically still in the shipping channel.

The Rip & Tides Warning: Always keep an eye on sea conditions throughout any shore or boat dive within "The Rip" (aka "The Heads"). This is a dangerous stretch of water, where Bass Straight meets Port Phillip, which has claimed many ships and lives. Please read the warnings on the web page diving-the-rip before diving or snorkelling this site.

Bass Strait Warning: Always keep an eye on sea conditions throughout any shore or boat dive in Bass Strait on Victoria's coastline. Please read the warnings on the web page diving-in-bass-strait before diving or snorkelling this site.

Crayfish Dive Site | © Ian Scholey

Divers have the opportunity to catch Southern Rock Lobster (aka Crayfish) at this dive site. Remember your catch bag, current Victorian Recreational Fishing Licence, rock lobster measure, and cray tags. Once you get back to the dive boat, or shore, make sure you clip the tail and tag your Crayfish as per Fisheries requirements. Please abide by all current fishing regulations if you intend to catch crays. See article-catching-crayfish for practical cray hunting advice from The Scuba Doctor, plus melbourne-cray-dives for a list of other crayfish dive sites near Melbourne. For tips on cooking your Crays, please see article-cooking-crayfish.

Boon Wurrung / Bunurong country

Traditional Owners — This dive site is in the traditional Country of the Boon Wurrung / Bunurong people of the Kulin Nation. This truly ancient Country includes parts of Port Phillip, from the Werribee River in the north-west, down to Wilson's Promontory in the south-east, including the Mornington Peninsula, French Island and Phillip Island, plus Western Port. We wish to acknowledge the Boon Wurrung as Traditional Owners. We pay respect to their Ancestors and their Elders, past, present and emerging. We acknowledge Bunjil the Creator Spirit of this beautiful land, who travels as an eagle, and Waarn, who protects the waterways and travels as a crow, and thank them for continuing to watch over this Country today and beyond.

Inner Corsair Wall Location Map

Latitude: 38° 18.130′ S (38.302167° S / 38° 18′ 7.8″ S)
Longitude: 144° 38.344′ E (144.639067° E / 144° 38′ 20.64″ E)
Datum: WGS84 | Google Map
Added: 2012-07-22 09:00:00 GMT, Last updated: 2022-04-26 16:17:53 GMT
Source: Unknown
Nearest Neighbour: Nepean Wall, 177 m, bearing 6°, N
Depth: 10 to 60+ m.

[ Top ]

DISCLAIMER: No claim is made by The Scuba Doctor as to the accuracy of the dive site coordinates listed here. Should anyone decide to use these GPS marks to locate and dive on a site, they do so entirely at their own risk. Always verify against other sources.

The marks come from numerous sources including commercial operators, independent dive clubs, reference works, and active divers. Some are known to be accurate, while others may not be. Some GPS marks may even have come from maps using the AGD66 datum, and thus may need be converted to the WGS84 datum. To distinguish between the possible accuracy of the dive site marks, we've tried to give each mark a source of GPS, Google Earth, or unknown.