Using the correct scuba diving cylinder is just as important to a diver's success and safety as how they configure their gear. A diver may go to an enormous effort to insure every hose, reel and accessory is exactly right only to 'drop the ball' by making the wrong cylinder choice.
The Scuba Doctor dive shop brings you scuba cylinders from the leading cylinder manufacturers in the world — Faber and Catalina — so you can not only get it done, but can get it done right.
No cylinder is perfect for every diver, or every diving situation. The Scuba Doctor offers the most complete selection of cylinders in the industry, allowing you to choose what is best for your unique needs.
All cylinders from The Scuba Doctor are suitable for nitrox service (i.e. up to 40% oxygen), visually inspected and shipped with a current hydrostatic date (except where indicated).
In Australia, scuba Tanks must be tested every year (12 months). We always ship cylinders with a current hydro test date. Due to manufacturing and import cycles, the popular sizes of cylinders typically have a factory hydro date less than 12 months old. However less popular sizes of cylinders may have a factory hydro date up to 24 months old as these are manufactured and imported less frequently.
As per the Australian Standards, the cylinders and valves we sell are for Imperial 0.750-14 NPSM (3/4 NPS) neck threads, NOT Metric M25 neck threads, and the valves have overpressure relief devices (burst discs). (Cylinders with Metric M25 neck threads do not comply with Australian Standards.)
The Faber steel cylinders have ISO 9809-1 markings. The Catalina aluminium cylinders have DOT-3AL2957 markings. All of these cyliners comply with Australian Standrads and are suitable for use in Australia. They may, or may not, meet the standards applicable in other coutries.
Scuba diving cylinders (USA: tanks, UK: bottles) are awkward and heavy, and if you fall down with one on you'll be lying on your back flailing your arms and legs in the air like a turtle flipped on it's shell.
Without scuba cylinders you can never be like that same turtle 'flying' gracefully through the water, experiencing a world that almost defies explanation.
Like all scuba gear, choosing a scuba diving cylinder/tank/bottle takes more thought and planning than just walking into a dive shop and grabbing the first thing you see.
There are a few different kinds of cylinders, each with their own pros and cons. Plus, not all diving cylinders can be used for all types of diving. The video below may help you to chose which dive cylinder is best for your needs.
Steel scuba cylinders have been around since the start of scuba diving, while aluminium diving cylinders came into use in the 1970s. Steel scuba cylinders are typically more expensive than the same capacity aluminium cylinders.
A steel diving cylinder is a lot tougher than an aluminium one, making it less likely to pit or dent. If properly cared for it will last longer than an aluminium cylinder. However, steel rusts with exposure to moisture and thus needs more careful care.
Because steel is stronger it can be handle higher pressures with a thinner wall thickness, making a steel cylinder smaller and lighter than an aluminium one of similar capacity.
Also If you want to use higher pressures (e.g. 300 bar), you will need to use a DIN valve which may make it hard to get refills depending on where you're diving.
Most technical divers use steel scuba cylinders, but they can be a good cylinder for regular recreational scuba diving too. The most common size is a 232 bar, standard 12.2 litre steel cylinder, but many women and those who use less air often prefer a lighter and smaller 10.5 litre cylinder.
Steel cylinders are more negatively buoyant than equivalent aluminium cylinders and only become less negatively buoyant as they are emptied. Thus they are popular in cold/temperate water areas where thick wetsuits and drysuits are used, because a steel cylinder means you can carry less weight on your weight belt.
Aluminium scuba cylinders came into use in the 1970s and are the most common scuba cylinders you'll find in tropical waters for recreational diving. Many dive shop, boat and resort operations use them worldwide.
The most common size used for diving is the aluminium 80 cubic foot (11.1 litre), but they can be smaller or larger depending on what they're meant to be used for.
For example, a bail out or pony bottle is much smaller than a standard size aluminium 80.
Aluminium cylinders being made of a softer, lighter material have thicker walls, making them larger and heavier than steel cylinders of the same capacity. Aluminium cylinders are relatively inexpensive and thus a good choice for most recreational scuba divers.
One downside of the aluminium scuba diving cylinders is that most go from being negatively buoyant to positively buoyant as they empty during the dive, so most divers wear a few extra kilograms (or pounds) of weight to compensate for this. There are a few models of aluminium cylinders that are built specifically to eliminate this problem, but like everything else, the more features it has, the more expensive it is.
Typically aluminium cylinders are certified for use at a working pressure of 200 to 210 bar. But some newer ones are available rated to nearly 230 bar. Again, these cylinders are more expensive and heavier.
Here are a few other things to consider before buying.
When purchasing scuba cylinders, the long-term advantages of steel's excellent buoyancy characteristics and long life make it the best choice for most divers, but especially those in cold and temperate waters. Choose a 232 bar steel tank size that meets your needs when it is under filled, putting an end to short fill concerns. For most divers this will be a 12.2 litre (100 cubic foot) cylinder, but some may prefer the smaller 10.5 litre (85 cubic foot) cylinder.
If your budget is tight, then aluminium cylinders initially costs significantly less. If going with an aluminium cylinder, avoid paints, and choose the brushed finish.
For both steel and aluminium cylinders you should choose a convertible valve having a DIN outlet with K (yoke) insert, often described as a 'DIN/K' valve. (That's why we provide this as our standard offering.).
Remember, the standard 207 bar aluminium 11.1 litre (80 cubic foot) capacity cylinder with a K valve is not a "one-size-fits-all" tank. Making the right cylinder choice can significantly improve your diving enjoyment. Please use this list as a guide when reviewing scuba diving cylinders and you should be able to find the right cylinder/tank to last you for years of diving.
For more help buying the best diving cylinder (Tank / Bottle) for you, please see our Buying a Scuba Cylinder guide.
The Scuba Doctor dive shop is your best source for scuba diving cylinders.
A marine radio operator certificate is required to transmit using VHF and HF radio. If you haven't yet got your VHF marine radio operators certificate do so now, you never know when you are going to need it. Oh! and learn the Phonetic Alphabet ASAP (see below).
Most of what's covered in this Tassie video is applicable for Victoria.
A marine radio is:
Marine Radio Victoria replaces Coast Radio Melbourne and provides a marine distress and emergency monitoring system for Victorian Coastal waters. Marine Radio Victoria uses a new VHF coastal network completed in 2017.
MF/HF radio for longer range communications is based in Charleville. Charleville Radio (VMC) monitors HF distress channels 24/7 and provides weather information services.
27 MHz radio is no longer recommended for marine use. Its broadcasting and reception is not as reliable as VHF and it is not consistently monitored along the Victorian coastline.
Distress and urgency communications can be made on the following channels:
Radio type | Channel/frequencies |
---|---|
VHF | 16 (67 alternative) |
27 MHz | 88 (86 alternative) |
HF (frequency) | 4125, 6215 and 8291 kHz |
VHF marine radios are a great asset to all who use them. They are not chat lines however, and should be used for working messages only. Misuse of the equipment could disrupt other users within the area. All VHF radio users are legally required to hold an operators licence and he vessel to which the radio is fitted must have a ship radio licence. A 'station' is a term for a VHF Radio. As a general rule listen to the channel for 30 seconds before transmitting to ensure it is not already in use.
VHF Channel | Purpose |
---|---|
16 | International Distress, safety and calling |
6 | Primary Inter ship |
8, 72, 77 | Inter ship |
12, 14 | Port Operations |
67 | Small Craft safety |
M, M2 | Marina Special Licence |
2, 24, 26, 28 | Ship to shore (public correspondence) |
6, 67, 73 | Search and Rescue Co-ordination |
VHF radios that are DSC enabled transmit a range of vessel identification information at the press of a button. This includes location information if connected to a global positioning system (GPS). If linked, search and radio agencies are able to get a good fix on your location, improving your chances of being located.
A DSC enabled radio must be linked to a Mobile Maritime Service Identity (MMSI) number for full functionality. A MMSI is a unique nine digit number that is entered into certain marine radio communications equipment, e.g. your DSC capable VHF radio. When using this equipment to send a distress alert, or to indicate some other emergency, the number assists emergency services to identify you and/or your vessel.
The MMSI number is issued by AMSA and applicants must hold a minimum of an Australian Waters Qualification radio certificate. See About Maritime Mobile Service Identity Information for why you need a MMSI, and how to apply for one.
Note: Best practice is to connect your boat's GPS unit to you VHF radio. Then the DSC transmission can automatically include your GPS location.
The range of VHF is line of sight and has an Inter-ship range of 25-40 kilometres. Ship to shore range is about 50 kilometres. The dual watch (D/W) facility allows you to monitor two channels via switching. Do not transmit on dual watch. Digital selective calling uses CRS but requires an additional kit for the radio set.
The capture effect is when a receiver within range of two stations will receive only the more powerful or closer signal, the other signal will be lost.
Aerial should be high and upright and clear of other aerials by at least 1 metre. An emergency aerial should also be carried.
Ship to shore - coast radio station
Inter-ship - station calling
Search and Rescue - Vessel in distress, relay station, Coastguard, on scene vessel / aircraft
Test Call / Radio Check - 10 sec
Calling on Channel 16 - 1 min
Calling again on Channel 16 - 3 min
Listen on channel before calling - 30 sec
[ Top ]
Marine Radio Victoria and some volunteer services monitor VHF Channels 16 and 67. Each station has an obligation to respond to a distress call: write down time, name, position, nature of distress, no of people on board and additional information.
If monitoring service says 'wait' this means they will respond within 10 minutes. Any longer than that should be given a reason prior. Only repeat things three times if it is a distress call. Other wise use their name once and your name twice. Distress calls should make the following 7 points in order:
Message | Meaning |
---|---|
Mayday (Distress) | Definition: When a vessel or person is in grave and imminent danger and requires immediate assistance. fire, accident damage, lee shore situation (under lee shore is when you are sheltered by the shore), diver not surfaced, man lost overboard, person is gravely ill. Example: MAYDAY, MAYDAY, MAYDAY. MAYDAY Evelyn Rose. My position is: 180 degrees, one mile from buoy number 1. I am sinking and require immediate assistance Four crew members on board, all safety equipment |
Mayday Relay | Definition: Mayday relays are transmitted when the station in distress cannot itself transmit a distress signal or when, although not in a position to assist a distress message is heard that has not been acknowledged. Example: MAYDAY RELAY, MAYDAY RELAY, MAYDAY RELAY. MAYDAY Evelyn Rose. Position is: 180 degrees, one mile from buoy number 1. Boat sinking and requires immediate assistance Four crew members on board, all safety equipment |
Pan Pan | Definition: When a station has a very urgent message to transmit concerning safety of a ship, aircraft or person. Example: PAN PAN, PAN PAN, PAN PAN Hello all stations, Hello all stations, Hello all stations My position is: 180 degrees, one mile from buoy number 1. I have been in a collision and require assistance of a tug. Note: Pan Pan Medico no longer exists. Just use PAN PAN. |
Seelonce Mayday | Definition: Imposing radio silence by controlling station |
Seelonce Distress | Definition: Radio Silence issued by other station MAYDAY - SEELONCE MAYDAY, |
Seelonce Prudonce | Definition: SEELONCE PRUDONCE is, or should be, announced when continuous silence is no longer required, when other brief communications are allowed on condition that the operators listen carefully before communicating to avoid interference when the frequencies are required by the stations involved in the rescue operations. |
Seelonce Feenee | Definition: Stations not participating in the rescue operations may not transmit on the frequencies being used for distress communications before the controlling station announces SEELONCE FEENEE. |
Securite | Securite, Securite, Securite Hello all stations, Hello all stations, Hello all stations My position is: 180 degrees, one mile from buoy number 1. My engine has broken down and I am anchoring in a southbound traffic lane, Request ships keep clear, over. |
NAME OF SHIP....................... followed by ship's name or call sign Aid required ............................... |
[ Top ]
The Australian Waters Qualification (AWQ) is the minimum mandatory qualification you must have to operate a VHF marine radio. Learn about the Australian Waters Qualification on the Australian Communications and Media Authority (ACMA) website.
The Office of Maritime Communications at the Australian Maritime College (AMC) is responsible for the management of Marine Radio Operators Certificates in Australia.
Marine radio qualifications and The Marine Radio Operator's Handbook are available through the AMC at amc.edu.au/industry/omc.
In an emergency, anyone aboard the vessel is permitted to use the radio(s).
Radio Command | Meaning |
---|---|
All after | Used after the proword 'SAY AGAIN' to request a repetition of a portion of a message. |
All before | Used after the proword 'SAY AGAIN to request a repetition of a portion of a message. |
Correct | Reply to repetition of a message that has been proceded by the proword's READ BACK FOR CHECK when it has been correctly repeated. |
Correction | spoken during the transmission of a message means - An error has been made in this transmission. Cancel the last word or group. The correct word or group follows. |
In Figures | The following numeral or-group of numerals are to be written as figures. |
In Letters | The following numeral or group of numerals are to be written in letters as spoken. |
I Read Back | If the receiving station is doubtful about the accuracy of the whole or any part of a message it may repeat it back to the sending station, preceding the repetition with the proword's I READ BACK |
I Say Again | I am repeating transmission or portion indicated. |
I Spell | I shall spell the next word or group of letters phonetically. |
Out | This is the end of working to you. The end of work between two stations is indicated by each station adding the word OUT at the end of the last reply. |
Over | The invitation to reply. Note that the' phrase OVER AND OUT is never used. |
Radio Check | Please tell me the strength and the clarity of my transmission. |
Received | Used to acknowledge receipt of a message, i.e, YOUR NUMBER...RECEIVED. In cases of language difficulties, the word 'ROMEO' is used. |
Say Again | Repeat your message or portion referred to i.e., SAY AGAIN ALL AFTER... SAY AGAIN ADDRESS etc. (Note:- This is typical of the need to memorise all these catch phrases'. To use the word REPEAT would be wrong REPEAT is used to emphasize. something). |
Station Calling | Used when a station receives a call which is intended for it, but is uncertain of the identification of the calling station. |
This Is | This transmission is from the station whose call sign immediately follows. In cases of language difficulties the abbreviation DE spoken as DELTA ECHO is used |
Wait | If a called station is unable to accept traffic immediately it will reply to you with the proword WAIT.... |
Minutes | If the probable duration of the waiting time exceeds 10 minutes the reason for the delay should be given. |
Word After or Word Before | Used after the proword SAY. |
Again | to request repetition of a portion of a radiogram or message. |
Wrong | Reply to a repetition of a radio telegram that has been preceded by the proword's 'I READ BACK, when it has been incorrectly repeated. |
[ Top ]
Letter | Code Word | Pronounced as |
---|---|---|
A | Alfa | AL FAH |
B | Bravo | BRAH VO |
C | Charlie | CHAR LEE |
D | Delta | DELL TAH |
E | Echo | ECK OH |
F | Foxtrot | FOKS TROT |
G | Golf | GOLF |
H | Hotel | HOH TELL |
I | India | IN DEE AH |
J | Juliet | JEW LEE ETT |
K | Kilo | KEY LOH |
L | Lima | LEE MAH |
M | Mike | MIKE |
N | November | NO VEM BER |
O | Oscar | 0SS CAH |
P | Papa | PAH PAH |
Q | Quebec | KEH BECK |
R | Romeo | ROW ME OH |
S | Sierra | SEE AIR RAH |
T | Tango | TANG GO |
U | Uniform | YOU NEE FORM |
V | Victor | VIK TAH |
W | Whiskey | WISS KEY |
X | X-ray | ECKS RAY |
Y | Yankee | YANG KEY |
Z | Zulu | ZOO LOO |
1 | One | WUN |
2 | Two | TOO |
3 | Three | TREE |
4 | Four | FOW ER |
5 | Five | FIFE |
6 | Six | SIX |
7 | Seven | SEV EN |
8 | Eight | AIT |
9 | Nine | NIN ER |
0 | Zero | ZEE RO |
See also, Wikipedia: NATO phonetic alphabet.
[ Top ]
Do | Do not |
---|---|
|
|
Read the information about marine radios and there use in the Victorian Recreational Boating Safety Handbook (Adobe PDF | 14.08 MB) — A downloadable version of Marine Safety Victoria's Victorian Recreational Boating Safety Handbook, July 2020.
Radio Safety Information (Adobe PDF | 403.94 KB) — How to make an emergency radio call. Print and laminate this and keep it on your dive boat.
Please also see Marine Safety Victoria: Marine Radio.
Copyright © 2005-2022 by The Scuba Doctor Australia, ABN 88 116 755 170. All rights reserved.
tel. +61 3 5985 1700 :: email. diveshop@scubadoctor.com.au :: Web site by it'sTechnical 2022