Nautilus Lifeline – An 18 month review

I eagerly awaited the arrival of my Nautilus lifeline (NL) some 18 months ago, and have carried it on every ocean dive I’ve done since (sorry guys, I’ve no logbook so can’t tell you how many dives it has done, but we’re talking 200-300). I’m pleased to say that I’ve not yet had to use it in anger, which is a pretty good thing in my book. With the unfortunate demise of my old website, so too was my old NL information page lost so I thought I’d build a new one.

I do a lot of deep diving, which regularly means long drifting decompression in the ocean under a surface marker buoy. Now if everything goes to plan, we deploy the buoy from depth and the boat will track the drifting buoy and pick us up several hours later, and often 5-10 miles from the original dive site. This is where the NL comes in, if the boat misses the buoy or leaves the site without us (intentional or not), I’ve got a last stand defense against being left in the ocean bobbing like a cork.

Our limited range tests of the unit worked fine, though I took away a few points:

  • Turn the volume up, as on a windy day in the ocean the lower volumes are difficult to hear (you’ll definitely need to remove your hood too)
  • The 3 second delay between when you push the talk buttons and when the voice communications actually get transmitted is far from intuitive. It contravenes normal radio operation and from my experience makes communications difficult if the user is unaware of this (easy to do in an emergency)
  • Hitting the RED button to initiate a DSC distress call is very easy to do, much more so than talking over a radio (particularly under stress). This is also well safeguarded against accidental presses too
  • Although changing the assigned VHF channel of either talk button in water is a feature, doing so is impractical and not something I plan to do (take charge of the VHF conversation and dictate channels to the other party)
  • The unit is positively buoyant and will float, though I still think a secure wrist tether is a necessary evil when using it to allow a hands free mode to attend to other tasks
  • I’m not too sure about the merit of the flashing strobe, it seems a little weak to be seriously useful but I’ve not real data to back this up
  • Replacing the USB charging cap is easily forgotten

Some features I’d like to see in the unit are:

  • A back-lit display and/or buttons (though I concede this may come with a serious power usage problem).
  • The ability to send an information based Digital Selective Calling (DSC) message (e.g. position report), as well as the distress message via an independent button.

Generally speaking the unit is small enough to fit in a dry suit pocket with ease, has a great depth rating of 130m (something we’ve tested many times), and the battery life in standby modes seems to be quite respectable (i.e. I’ve not noticed any dramatic drop in the battery level whilst not in use). If you haven’t read between the lines, I’m a big fan of this device and think it is worth every cent.

VHF Certification, DSC & MMSIs

Now this is where it starts to get a little silly. In Australia in order to use any VHF radio one is required to have a Marine Radio Operator VHF Certificate of Proficiency (MROVCP), which you need to do a short course and exam for (cost is about $150). As far as I can tell, anyone can use a VHF radio in the event of an emergency; that is if you were a passenger on a boat and the skipper (captain) was lost at sea you’d be fully entitled to pick up a VHF radio and call for help; or better yet initiate a DSC distress call. I ask then why can’t someone carry a NL and only use it in an emergency? The answer in my view is nothing, but I am NOT a lawyer and can’t confirm the law on this matter.

Unfortunately to enable the RED distress button you need to have a MMSI. In Australia these are issues by AMSA and also require a MROVCP, so to get the full capability out of the NL you need to do the course. What I also learnt in my VHF journey is that in other parts of the world MMSI numbers are issued freely (e.g., and that you can practically put any 9 digit string into the NL in order to enable the DSC feature. The one down side to using a fake MMSI (or one not issued in Australia by AMSA for Australian waters), is that in Australia when the DSC distress call is initiated, the MMSI won’t be able to be reconciled against a database of MMSI numbers. I’m no expert here, but I’m sure the rescue agencies will still come and get you, and boats in the immediate area don’t have that database anyway so will be none the wiser. I consider this analogous to an international yacht travelling into Australian waters and making a DSC distress call with a foreign MMSI.

Boat Information Card

As I dive on many boats, commercial and private, I’ve put together this little card that I give to new skippers (captains) that describes the NL and how I use it. from my experience to date I’ve found that skippers are very welcoming of such information as many had never heard of the NL before. I’ve also encountered about 20-30% of commercial charter boats that don’t have DSC enabled VHF radios, and slightly more recreational boats without them too as VHF is more of a commercial frequency in Australia. On the back side I’ve also included our red/yellow surface marker buoy protocol, though I understand this may not be everyone’s cup of tea. For reference, here is a word document for those wanting to do a similar thing – the template is free and re-use or modification is welcome without permission.



Disclaimer: I don’t sell or have any relationship with Nautilus Lifeline. I paid full retail for my unit and am just sharing my experiences with fellow divers and boaters in order to increase safety.