Candice LandauLast Updated on May 16, 2026 by Candice Landau
Note: You can buy the Nautilus LifeLine NexGen on Nautilus’ website. Click this link and use my coupon code: scubascribbles10. You’ll receive a 10% discount. This is an affiliate code and it helps me pay for hosting this site (and providing you in-depth information free of advertiser bias). My review is not connected to being an affiliate at all!
Over the years I’ve become more paranoid about safety. You can call it getting older, or you can put it down to experience. I’ve seen things go wrong in the field, on the dive boat, and in the water. And, no matter how good the dive operator, accidents happen. Often, there’s a good outcome—people are rescued and the mistake isn’t fatal. But sometimes…sometimes there isn’t a happy ending.
While you can’t control factors like the weather, how well a boat is maintained, or whether or not the captain is having a good day, there are things you can control: your own safety preparedness. If you’re equipped with both the right knowledge and the right gear, you nudge your odds of a positive outcome in the right direction if things do go wrong.
As an active diver, I’m ashamed to tell you that I only purchased a marine rescue GPS six years into my diving career. When you consider the type of diving I was often doing—diving in the dark, cold current-ridden waters of Oregon and Washington State—this is almost shocking. The thing is, most of the divers around me didn’t wear them or even think about them. No, not even the professionals.
I’m not going to spend my time wondering why this was the case, but I will say that over time, marine rescue GPS units have become easier to use and more affordable. Today, if you’re an active diver, in my opinion, you’re crazy not to wear one on every dive.
Though I’ve wanted to write about my Nautilus LifeLine for some time, it wasn’t until I upgraded to their newest model, the Nautilus LifeLine NexGen that I finally decided to do it. I hope this review and overview will nudge you to purchase your own. As an ambassador of all things safety related, I can’t tell you how much you’ll appreciate just knowing you have this on your next trip.
What made me finally buy a Nautilus LifeLine?
I was one year into my job at Scuba Diving magazine when an opportunity to dive and write about diving on the Island of Hawaii came up. And so, boyfriend in tow, I flew into Kona for a week of sampling all the big island had to offer.
Almost every day began the same way: a calm boat ride out of the harbor, dolphins torpedoing below us, sun bright and high in the sky. Most passengers were happy and calm. After all, they were on vacation. Conversation was upbeat and with experienced boat captains used to doing this on the daily, worry was at a minimum.
On one such day, we decided to pick a dive site known for having both black coral and some really iconic volcanic features—arches, swim throughs and sharks. The catch was the water was a little choppier than our usual sites because the site was close to shore and shallower. Unperturbed, we all did our back rolls and sank into the blue for the dive.
It was a beautiful dive and in addition to seeing black coral for the first time, I also saw plenty of sharks, a couple of giant manta rays, and an abundance of reef life. When I surfaced, happy and ready to chat about the dive, I was met with a very different scene from the one I’d left.
The sky was still bright, perhaps even more so, but the surge had picked up, so much so that for a while, my group—dive guide included—couldn’t even see the dive boat. It didn’t help that a strong surface current was rapidly pulling us away from shore.
SMB still inflated, we waited for the boat (and the one person on it) to spot us. It can’t have been more than five minutes but it felt like much longer because we knew the captain hadn’t seen us and wasn’t taking his time due to picking up another person—the whole group was together. The truth was, with the bright sun and the high surge, he simply couldn’t see the regular-sized SMB or our tiny bobbing heads.
When he did finally spot us, he was quick to head our way. Due to the ocean conditions, we changed our plans and made a subsequent dive in a sheltered cove near the harbor. Though the rest of the day went to plan I couldn’t stop wondering, what would have happened if the captain hadn’t spotted our group? How far might we have drifted? Who would have rescued us?
Looking back, I’d change four things: I’d have a signaling mirror (or a wrist mirror), I’d have a longer SMB, I’d have a couple more members of the group inflate their own SMBs, and I’d have a marine rescue GPS. With a unit like the Nautilus LifeLine, not only is it easy to activate an emergency signal, but it’s also got a feature most divers don’t know about, a positioning signal, that can alert boats as to your position instead of an emergency. When you’re in a situation like the one I was in—drifting further from the boat in high surge, but not yet in danger, this is the perfect option.
Since then I’ve dived in many destinations where drift diving makes the likelihood of getting pulled out to sea far more possible—Galapagos, Cozumel, Palau, Komodo, the Maldives. In each of these locations, I’ve worn my Nautilus LifeLine and been grateful for it—just the knowledge that it’s there allows me to enjoy my dives more fully.
Interestingly, only two operators I’ve been with on my many travels have required divers to wear these units—the dive boat in Galapagos (Galaxy Diver II, who also supplies them), and Horizon Divers in Cozumel (supplied as well). This is of course a great point in favor for each of these operators suggesting that they do take safety seriously.
I do encourage you to label your unit as if others have them you could get it mixed up. I buy my labels from My Scuba Label ID on Amazon (they’re customizable). They’ve held up for years and are 100% waterproof. They also have a lovely pearly sheen.
Some operators will rent them out, but honestly, I’d prefer to use my own as I know it works and has been set up correctly. More on that in a second.
Let’s dig into the nitty gritty details
The Nautilus LifeLine NexGen is a marine rescue GPS that helps divers stay safe at sea. Sailors, kayakers, snorkelers, boaters, or anyone else who spends time on or in the water would also benefit from owning one. They’re light, easy to attach and slightly positively buoyant meaning they’re unlikely to sink.
There’s no monthly subscription fee (just the fee you pay upfront to purchase the unit) and learning to operate one is simple. For $249 (less than a dive computer or regulator), divers can purchase their own. If you already own one and want to upgrade to the newest model, you can trade yours in and pay just $135.
I chose to write a review of the Nautilus LifeLine NexGen in particular because I wanted to upgrade mine and because I consider it an essential, non-negotiable part of my dive equipment, as important as my regulator. Yes, I’m that serious.
The unit has both GPS and marine radio function and is accurate to within 1.5 meters, which is insane when you consider the size of the ocean. It has a rescue range of up to 34 miles and is universal, meaning it will work with modern DSC-equipped VHF marine radios, as many handheld radios do not include DSC functionality. Though the unit is rated to 425 feet it’s actually been tested, without issue to over 700 feet of depth. It has 5 years of battery life and a 98 hour transmit time (if you’re lost at sea for that long, I’m sorry, you’ve got real problems). The whole unit weighs just 4.6oz (131g) and that’s with the batteries included. On that note, batteries are affordable and easy to find. Simply place an order on Amazon.
The Nautilus LifeLine NexGen also comes with a factory programmed MMSI number (Maritime Mobile Service Identity) which is a unique 9-digital number assigned to the unit and that will be picked up in DSC radios and AIS units—more on those two in a second. In short, you don’t need to buy the number, though you DO need to register it to enable DSC communications. This is actually something a LOT of divers who purchase one don’t realize. READ this paragraph twice.
First impressions and unboxing
Okay, I won’t lie, my first impression of the Nautilus LifeLine NexGen was: Did they accidentally send me the old model?
Even though the NexGen sticker was on the unit as it is in pictures on the site, the unit itself is pretty indistinguishable when compared to the previous model. The truth is, it’s the tech that’s updated, not the packaging and that’s because the packaging works. Don’t change it if it ain’t broke, right?
It still comes with a screwdriver so you can add and change batteries. And it still comes up with the little odd orange-looking twisty widget that allows you to roll the antennae back up if you’ve deployed it. It’s actually called the antennae winder. If you lose yours you can buy a new one on the company’s website for $3.99.
I do find the screwdriver a little too small, personally and have a separate one so that I can get more leverage if the screws on my unit become a bit salt-encrusted with time. If you’re a bit of a gear head like me, I highly recommend buying a set of tiny screwdrivers. I use these for my underwater photography equipment too.
The unit is packed neatly in sponge and the whole thing is compact and well protected.
Personally, I would have liked to see the instruction booklet in the box, not least because I think a lot of people won’t know how to set it up properly (activate DSC) or how to use it NOT on emergency mode but just to send a positioning alert.
For something designed for safety, I think safety instructions should always be made abundantly clear from the outset.
If you’ve purchased your own unit, don’t wait to download the iphone or android app to register your serial number and begin using it.
You’ll also need to purchase CR123 3V (1550 mAh) batteries. I got mine on Amazon for $14 for a set of six batteries.
One thing to note is that if you buy the unit alone, it does not come with the neoprene or silicone pouch or the lanyard. I think that’s okay. I’ve never used either and haven’t had any issues with mine. It certainly doesn’t leak and I’ve figured out my own method for attaching it. However, if you’d like an easy way to attach yours, consider looking through their online store.
Personally, I wouldn’t pop one of these in a BCD pocket and “forget it” because it is slightly positively buoyant. Should your pocket accidentally come open, you might lose your LifeLine. I’d recommend attaching a bolt snap, or double ender, or something that allows you to keep it clipped off at a minimum. The company does sell a lanyard with two D rings that allows for the unit to be both used and clipped off at the same time. It costs $8.99 and is a slick and simple solution to the problem.
Setting up the Nautilus LifeLine and using it
The first thing you’ll want to do when you get your Nautilus LifeLine NexGen is download the app. This will allow you to register your device and get it set up for DSC radios. If you don’t do this, your unit will only work on AIS technology and if boats in your area don’t have that, well you’ll have missed out on a core safety feature. The app will guide you through the setup.
If you have questions, I strongly urge you to email the company. They’re very responsive.
How to Use the Nautilus LifeLine in an Emergency
The Nautilus LifeLine can only be deployed at the surface. If you open it at depth you’ll flood it and it won’t work. That said, it’s waterproof to 10 feet so if you open it at the surface and it gets splashed it will be fine.
To activate or test it, simply open the catch (the metal buckle) and open the lid. Now, lift the dome-shaped antennae cover off the device. The antennae should spring up.
Press the blue button to turn the unit on. It should start flashing. To test it (or activate positioning mode), press the yellow button. If you’re in an emergency situation, press the red button. It will also start flashing.
You are now transmitting. Hold the device as high as you can with the aerial extended above you. According to the company, 34 miles is the maximum demonstrated range using a high-elevation receiving antenna. Actual range depends heavily on how high the unit is held, sea conditions, and receiving antenna height. Once you’ve activated the unit, a DSC and AIS notification will be sent. Note, boats need AIS-equipped technology to receive this. They’ll get your location accurate to 1.5m.
To maintain the unit, check the o-ring is free of dust, salt, grit, hairs, etc. Do NOT use silicone on the o-ring as it’s a compression o-ring. It does not need it.
In-Water Testing
I’ve used the Nautilus LifeLine NexGen (the newer model) in St. Eustatius, Komodo, Madeira, Saba, the Bahamas and Vanuatu. I did take it to 140 feet in Vanuatu and did repeated decompression dives on it. It still works when I hit the test button and does not appear to have leaked.
The previous unit I had (the model before NexGen) has definitely stood up to some serious technical diving too, including to almost 200 feet in the Red Sea and in Chuuk Lagoon. At no point have I had issues with leaking, with the o-ring, or with testing it. I have replaced my batteries once, purely out of paranoia rather than need, but other than that, its safe to say that I’ve put it through some action and have yet to have an issue.
I decided to create my own DIY attachment mechanism on the first unit—a simple stainelss steel bow shackle with a swivel-eye bolt snap and some rescue tape on the bolt snap to mark it as mine. I simply transferred that attachment to the new device when it arrived. I think if I were going to improve it further, I’d add a wrist lanyard just so that if I ever have to deploy it, I don’t lose it or drop it (though it is positively buoyant so there’s that…). I also carry it in a little neoprene can sleeve so it doesn’t get dented or banged about when I’m traveling. I bought a pack of these and use them to protect my other equipment when traveling too, including my Shearwater dive computers and my DJI action camera.
The unit cannot be deployed underwater which might be obvious but you’d be surprised by what people think. Once deployed it’s still waterproof and watertight down to 10 feet so you really don’t need to worry about it getting dunked or splashed in stormy seas—it will still work.
I’m very grateful the buttons flash as otherwise one might not know if they’d turned it on. This is something you can get familiar with when you buy yours and I encourage you to do so. I even encourage you to take off the cap and practice deploying the antennae (though putting it back is a bit of a pain—you will need the antennae winder and maybe even a bit of help from a second person). Obviously, don’t activate rescue by hitting the red button when you test, but do hit the yellow button to test! That’s also how you activate the positioning mode.
I’ve tried using it with thick wet gloves, dry gloves and bare hands and at no point have I had issues. I suppose this depends on your own dexterity and comfort but it’s completely possible to use it as is.
I haven’t tried to use it with the silicone cover on it but I would imagine that in an emergency I wouldn’t care if I had to rip the cover to deploy it.
I think, on my next trip and providing the boat captain is amenable, I will try to activate the positioning signal to see if they pick it up. I won’t test the emergency signal as I obviously don’t want to cry wolf!
That being said, I think the next time I get on a dive boat or better yet, book a dive boat, I’ll also be asking if they have DSC radios and AIS technology.
What I liked
There are loads of things to like about the Nautilus LifeLine NexGen, not least of which is it’s an affordable way to ensure you’re safer on the water, but here’s my full list:
- It’s compact, user-friendly and gives you peace of mind.
- It’s simple to operate. No frills or complexity and instructions stuck onto the unit body.
- The range and accuracy are second to none.
- It offers AIS and DSC signaling for maximum likelihood of getting picked up.
- You’ll know you’ve pushed buttons because they’ll flash (basically it will tell you).
- Even with the cap open or off, it’s still waterproof to 10 feet (though you don’t want to go deeper than that.
- The positioning alert feature is super cool. Say you’re a new or nervous diver and you don’t want to send a distress signal but you also think the boat can’t see you. Take your unit out, turn it on until the blue button is flashing, press the yellow test button. You are now position alerting. According to the company, radios will show position alert accurate to 1.5 meters. Of course, you may want to tell your dive guides or boat captain this is possible as they likely don’t know themselves. In fact, I’d guarantee they don’t know.
What could be better
- Access to instructions. For a safety device, I’d make sure to include printed instructions in the box. I think many people won’t take the extra step to read instructions if they have to find them online.
- A way to attach the unit to one’s gear or body out of the box, without having to make or purchase a separate piece.
- Instructions on curling the antennae back up using the antennae winder (I had to figure this out).
- Instructions on how to use the positioning feature. (Though be aware, use of this feature is prohibited in some European countries—just the positioning feature).
- A note on setting up DSC out of the box. Most people won’t realize that otherwise the unit will only work on AIS technology.
Comparison to other devices
Garmin also has a marine rescue GPS made for divers but I’ve chosen the LifeLine because Garmin has a subscription fee and at the end of the day, that makes their unit a lot more expensive. Plus, Nautilus LifeLine is made for divers and people in and on the water. It’s not an all-purpose device mainly used by hikers and people going off the grid. Furthermore, Garmin’s InReach device is actually now illegal in some countries because it allows for satellite communication in off-the-grid areas. Garmin has a note about this on their own site too.
Don’t get me wrong, I love Garmin and own a Garmin dive computer but a subscription fee for safety? That’s a no from me.
Final verdict
As a whole, I couldn’t recommend this unit more. I’ve put it to the test, used it on deep technical dives and in high-current, rough surge dives, and have never had an issue. To this day, mine still works well and gives me the added benefit of peace of mind when I dive.
I recommend that anyone who does any sort of water activity purchase one. This includes divers, kayakers, snorkelers, boaters, and paddle boarders.
I also recommend you keep this in your dive kit, even if you don’t think you’ll need it. You never know. Put it in a pocket, clip it to your belt or a D-ring. It adds almost no weight and gives you peace of mind.
Where to buy and cost
I recommend buying the unit directly from the company itself. I try to always do this when it comes to safety equipment as the company will be incentivized to send out devices in-date and to spec.
You can get a 10% discount if you use my coupon code: scubascribbles10 (click this link) but don’t have to. Obviously that helps me pay for things like hosting this site and the tools I use to keep providing information like this free of charge, but it’s completely up to you! Either way, I want you to own and use one of these to make your diving and water activities safer.
As I mentioned previously, unlike the Garmin InReach, there’s no monthly subscription fee. The cost of the unit is $249 and that’s it. You can soup it up with attachments and gadgets for a little more but you don’t have to.
If you own an old Nautilus LifeLine, you can trade it in and get the new one for just $135. And, if you have any questions, check out the company’s FAQ page. It’s a good resource.
