Tech Tip:
Will back inflation float an unconscious diver face up?

We usually hear this from divers who have always worn a jacket style BC, and we'd like to point out that it's irrelevant. It's true, that boating regulations require an approved wearable Personal Floatation Device (PFD) to float the unconscious victim face up in the water. But a Buoyancy Control Device (BCD) for scuba divers is not designed to be a PFD for an unconscious boating accident victim, regardless if the BC is jacket or back inflation.

We offer back inflation style options because experienced divers have learned the back inflation BCD is better than a jacket BCD, offering very precise control of buoyancy and trim as well as offering a more streamlined profile. An improperly fitted back inflation BCD might cause you to tip forward, but a properly fitted back inflation BCD, worn with a crotch strap, will allow you to assume and hold any position under the water, or on the surface.

When on the surface, divers new to back inflation will need to break the habit of holding down the power inflator until they feel squeeze (there won't be any), or hear the OPV release. With an over inflated air cell they will have a huge amount of buoyancy on their back, causing them to float too high in the water and tip forward. Instead, they should add only enough gas until their head is just above the water.

Finally, a very common error when selecting a back inflation BCD is to choose an buoyancy aircell (called a 'wing') that is much too big, causing a 'taco effect' that makes managing buoyancy considerably more difficult. The cylinder size, type and configuration, not lift capacity, is the best guide to selecting the correct wing. While many doubles wing designs can be adjusted for occasional use with singles, keep in mind they are not designed to be used primarily as singles wings and they are not optimal with singles. Unless you are diving one of the very large steel cylinders, a 30 lb (14 kg) is about the maximum lift you need for single tank sport diving.

Nelson Bommie

Bommie Dive | Boat access

Depth: 2 m (6.56 ft) to 20 m (66 ft)

Level: Open Water and beyond.

Nelson Bommie is a boat diving and snorkelling site which lies offshore from the shifting Glenelg River mouth, south of the Nelson township, near the South Australian border, on Victoria's Discovery Coast. This is the western most dive site in the listings.

Diving and Snorkelling at Nelson Bommie

Location: Nelson, Victoria 3292

Ideal Conditions: Diving Nelson Bommie requires calm conditions and a very low swell. See WillyWeather (Glenelg River Offshore) as a guide for the tide times and the height of the tide.

Boats can be launched at the Glenelg River - Kellett St Boat Ramp, the Glenelg River - Old Bridge Rd Boat Ramp, the Glenelg River - Isle Of Bags Boat Ramp, or the Glenelg River - Simsons Landing Rd (Waterski club) Boat Ramp.

Abalone Dive Site
© Mark Norman, Museum Victoria

Divers have the opportunity to catch Abalone at this dive site. Remember your catch bag, legal abalone tool, current Victorian Recreational Fishing Licence, and abalone measure. Please abide by all current fishing regulations if you intend to catch abalone.

See article-catching-abalone for practical abalone hunting advice from The Scuba Doctor, plus melbourne-abalone-dives for a list of other Abalone dive sites near Melbourne.

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.

Gunditjmara country

Traditional Owners — This dive site is in the traditional Country of the Gunditjmara people of far south-western Victoria which continues over the state border into a small part of south-east South Australia and is bordered by the Glenelg River to the west and the Wannon River in the north. This truly ancient Country extends 100 metres out to sea from low tide and also includes Deen Maar (aka Lady Julia Percy Island) where the Gunditjmara believe the spirits of their dead travel to wait to be reborn. We wish to acknowledge the Gunditjmara as Traditional Owners. We pay respect to their Ancestors and their Elders, past, present and emerging.

Nelson Bommie Location Map

Latitude: 38° 3.987′ S (38.066454° S / 38° 3′ 59.23″ S)
Longitude: 140° 59.003′ E (140.983378° E / 140° 59′ 0.16″ E)
Datum: WGS84 | Google Map
Added: 2022-05-19 12:18:09 GMT, Last updated: 2022-05-23 16:08:40 GMT
Source: Peter Ronald GPS
Nearest Neighbour: The Boatshed, Cape Bridgewater, 50,638 m, bearing 132°, SE
Nelson, Discovery Bay, Discovery Coast.
Depth: 2 to 20 m.

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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.