The Scuba Doctor has a great range of quality dive computer solutions for technical and rebreather divers.
At the risk of annoying those who do have a preference for a specific decompression algorithm, the simple answer for most divers is NO the algorithm is not critical. There is no expert consensus that any one of the current crop of decompression algorithms is better than another. All of these algorithms used in dive computers and desktop table generation software, when set to their default conservancy values, will get you out of the water with an acceptable margin of safety. What we can say for sure is they are all imperfect representations of actual decompression in humans.
Numerous variants of ZHL-16C are very widely implemented in both sport and technical dive computers. For technical diving, versions of ZHL-16C that include user configurable Gradient Factor modifications are very popular because the GF values can be 'tuned' to provide different types of profiles for specific types of diving. VPM-B dive profiles typically have deeper initial stops, along with reduced time at shallow depths resulting in a 'smoother' profile although recent research calls into question the benefits of 'deep stops' especially for lengthy VPM-B profiles. DCAP was developed for use by early extended range divers (today we call them 'technical divers'.) VVAL-18M is the basis for the modern US Navy Tables. DCIEM has been extensively tested by the Canadian military to ensure its applicability to cold water working divers. RGBM (basis for NAUI tables with its roots in VPM) and DSAT (basis for PADI tables) are most often seen in no stop required sport diving applications. Recently, the RGBM model has been called in to question by a legal action, but it's not clear if the issue is with the algorithm itself or a specific dive computers' implementation, as most experts consider the RGBM model to be very conservative especially on repetitive dives.
The practices of decompression are not exact, in many ways as much about skill as science. Much of what we do in decompression diving is based on empirical observation and experience, rather than having a basis in theoretical science. Dr. R W (Bill) Hamilton, the late co-developer of DCAP and whose research in decompression is widely acknowledged as having a key role in opening up recreational extreme exposure diving in the early 90s, was fond of the saying 'what works, works'. The most important safety factor is not the decompression algorithm you select, rather your skill as a diver and that you closely follow the recommendations of that algorithm and safe diving practices in general. Also, best practice when diving as a team is that all divers should use the same algorithm in order to remain together as a team during ascent phase of the dive plan.
Wreck Dive | Shore access
Level: Open Water and beyond.
The New Zealander shipwreck lies in Portland Bay, on the Discovery Coast of Victoria in 3 metres of water. While it is a pleasant shore dive, the wreck is easiest found from a boat.
If you check out the January 2017 Google Earth image, you get a perfect outline of the New Zealander hull.
Shore access to the New Zealander shipwreck dive site is from the northern end of Nuns Beach. The beach lies immediately north of Portland Harbour. The harbour construction resulted in erosion of most of this beach and exposure of the backing cliffs.
Some sand accumulated on the northern side of the harbour breakwater to form Nuns Beach. In addition, a groyne has been built at the northern end of the 300 metres long, east-facing beach. In 1990, sand from Pivot Beach was dumped here to replenish the beach. The beach is well protected by Cape Nelson and the harbour walls. Waves average less than 0.5 metres which, with the fine beach sand, ensures a low, shallow beach and attached bar.
When dived from a boat, access is from the Portland Harbour, Lee Breakwater Road North Ramp or the Portland Harbour, Lee Breakwater Road South Ramp. The GPS mark should be right on.
Best dived in good conditions with a low swell with light north or northerly winds. See WillyWeather (Portland Bay) as a guide for the tide times and the height of the tide.
{{southern-ocean-warning}}The New Zealander was a three-masted wooden sailing ship of 1,309 tons, built in 1852, at Pictou, Canada. The vessel was 174.2 ft (53 m) long, with a beam of 34.4 ft (10 m), and a depth of 23 ft (7.01 m).
The New Zealander departed on 23 August 1853 from Liverpool to Australia carrying 465 assisted passengers. The immigrants were mainly Irish (103) and Scottish (362). After unloading the passengers, and 16 days in Portland, the vessel underwent an extensive refit. 18 of the original crew had to be jailed for failing to prepare for the return journey.
On Friday, 16 December 1853, after Captain Brown had tried to muster a new crew, the ship was found ablaze at 4 a.m. It was towed to the beach at Whalers Bluff and continued to burn. One theory at the time was that the cook set the ship alight because the crew had wanted to go ashore, whilst another theory was spontaneous combustion of the coal cargo, fuelled by the new varnish which kept the hull burning. The vessel burned for 2 to 3 weeks and was visible for many years above the water at the foot of the lighthouse. Spruce, pine, birch, iron hanging knees, yellow metal.
See also, west-coast-shipwreck-trail,
Heritage Council Victoria: New Zealander, and
Australian National Shipwreck Database: New Zealander.
Heritage Warning: Any shipwreck or shipwreck relic that is 75 years or older is protected by legislation. Other items of maritime heritage 75 years or older are also protected by legislation. Activities such as digging for bottles, coins or other artefacts that involve the disturbance of archaeological sites may be in breach of the legislation, and penalties may apply. The legislation requires the mandatory reporting to Heritage Victoria as soon as practicable of any archaeological site that is identified. See Maritime heritage. Anyone with information about looting or stolen artefacts should call Heritage Victoria on (03) 7022 6390, or send an email to heritage.victoria@delwp.vic.gov.au.
Over the years we've been provided with different GPS marks for the New Zealander. The GPS marks we know of in circulation for the New Zealander are:
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.
New Zealander Location Map
Latitude: 38° 20.287′ S (38.33812° S / 38° 20′ 17.23″ S)
Longitude: 141° 36.620′ E (141.610341° E / 141° 36′ 37.23″ E)
Datum: WGS84 |
Google Map
| Get directions
Added: 2012-07-22 09:00:00 GMT, Last updated: 2022-05-23 18:50:52 GMT
Source: GPS (verified)
Nearest Neighbour: Lighthouse Reef, 239 m, bearing 224°, SW
Three-Masted Wooden Ship.
Built: Pictou, Canada, 1852.
Sunk: 16 December 1853.
Portland Bay, Discovery Coast.
Depth: 3 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.
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