Which inflation system is right for your lifejacket?

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Which inflation system is right for your lifejacket?

Updated for 2021: TeamO lifejackets now have four different inflation system options, which have different pros and cons depending on the type of sailing you are planning on. Here is a quick guide to help you decide which one is right for you.

We're always happy to talk, so there are contact details are at the bottom of this page if you still have any questions after reading the guide.

UML ProSensor Elite Firing Head

TeamO Ocean and Offshore lifejackets come with the ProSensor Elite Firing Head fitted as standard and are our preferred inflation system for these models because they perform consistently well and rearming kits are widely available at chandleries around the world. If you have cruised from Europe to the Caribbean and need to rearm your lifejacket when you get there you can bet you'll find a ProSensor Elite rearming kit stocked in a chandlery in one of the marinas or ports there!

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How it works: The UML ProSensor Elite firing head works using a water activated system. A compressed paper capsule is contained within the firing head. When water washes in to the bottom of the grey unit the paper pellet becomes wet, dissolves and releases a spring which fires the CO2 cylinder and inflates your lifejacket.

The firing head is designed so that water must travel upwards inside the unit to dissolve the paper pellet. It is then also protected by the lifejacket cover. This means that spray and rain will not cause accidental inflation.

Lifejacket cylinders before and after use, used lifejacket cylinder, used lifejacket cartridge, lifejacket cartridge

Above: Lifejacket CO2 cylinders before and after use. On the left you can see the new cylinder is sealed, there is no hole in the bottle at all. On the right the bottle has been punctured by the firing head, which means the CO2 has been used and the bottle must now be replaced when you service your lifejacket or rearm it for future use before you go sailing. 

There are two colour tabs on the front of the unit to show the activation status as shown in the image above. When both the firing head and the CO2 cylinder show as green marks the lifejacket is armed and ready for use. Both of the tabs need to show green before you go sailing. If one of the tab marks shows red this indicates that the jacket is not armed and needs to be checked.

If the top tab shows red check this means that the CO2 cylinder needs checking. It may have been punctured and need replacing, or it may mean it is not screwed firmly enough in to the grey unit. You can unscrew the CO2 cylinder by hand and check the bottom of the bottle. If it has been punctured it will have a small hole in it, like Co2 cylinder on the right in the image above. This means that the bottle has been used and must be replaced.

If the bottom tab mark on the grey unit shows red check the bottom cap on the firing head. It may have been used and need replacing or it may mean it is not screwed firmly enough in to the grey central unit. To check, look at the bottom of the grey bottom cap. There are holes in it, as shown in the image below. Through the holes you should see a red plastic circle with a white paper ring surrounding it. If you can only see the red plastic circle then the cartridge has been used and needs replacing.

TeamO now also offers the UML Conversion Kit for the ProSensor Elite inflation system. This is a plastic cap that fits securely over the end of the ProSensor Elite head and converts the system from an automatic inflation system to a manual system. When this cap is in place the lifejacket user must manually pull the plastic toggle to inflate the lifejacket, it will no longer inflate automatically. Some sailors like to have the conversion kit onboard to allow them to switch easily between both the automatic lifejacket and manual lifejacket modes. 

ProSensor Elite inflation systems expire after approximately 3 years and you should check the date which is printed on the side of the grey unit before you go sailing. We recommend that you service your lifejacket annually and replace the ProSensor Elite inflation unit at least 6 months before it's stated expiry date. 

The TeamO Range: The UML ProSensor Elite is compatible with TeamO's Ocean and Offshore BackTow Lifejacket models. 

Hammar Firing Head

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The Hammar inflation system looks very different to the UML ProSensor Elite, and it works in quite a different way too. The system is based on using water pressure to release a spring and inflate the lifejacket. Unlike the Pro-Sensor Elite described above, the Hammar firing head requires immersion in water to activate - the yellow cap shown above needs to be approximately 10cm underwater to achieve enough water pressure to activate the unit. 

Water enters the unit from the spout shown on the top right hand side of the yellow unit. As water fills up inside the unit the pressure increases until it is high enough to trigger a pin inside the casing. Once fired the pin punctures the CO2 cylinder which is stored inside the bladder lung, causing the lifejacket to inflate.  

The Hammar system is intended for use in more extreme sailing conditions where you are likely to be experiencing waves over the deck or similar - it is therefore often favored by sailors doing deep ocean and longer offshore sailing as it is less likely to inflate accidentally. Sailors with very wet boats or anyone working on the bow may also find that the Hammar inflation system is a good fit for them.

Hammar inflation systems expire after approximately 3 years and you should check the date on the front of the yellow unit before you go sailing. We recommend that you service your lifejacket annually and replace the Hammar inflation unit at least 6 months before it's stated expiry date. 

The TeamO Range: The Hammar inflation system is only available in the TeamO Offshore BackTow model. 

Manual Firing Head  

UML Micro Manual Lifejacket inflation system, which lifejacket is right for me,

The UML Micro Manual Inflation units have recently been relaunched so that they are even smaller and lighter than previous editions. They are much more simple than the other systems described above - there are no paper pellets or water-pressure activated systems here. Simply pull the yellow toggle as shown above to inflate the lifejacket. 

Manual lifejackets are sometimes favoured by sailors who want to have more control over when they do or do not inflate their lifejacket. If you have concerns about entrapment on boats (for instance, on multihulls in a capsize situation) you may want to have a manual lifejacket so that it does not inflate before you want it to. It may also be suitable for sailors who are sailing in more extreme conditions with a lot of water on deck or over the sailors, in situations where the water may accidentally inflate an automatic system.

Generally we advise sailors to seriously consider the automatic inflation systems first because they protect the wearer in the event that they end up in the water in a compromised situation (for instance, if they were not conscious when they entered the water). An automatic inflation lifejacket will inflate in this situation and the lifejacket is designed to turn you face-up in the water without any further action by the wearer, so that the Man Overboard/Person Overboard/MOB does not drown. 

The TeamO Range: The UML Micro Manual lifejacket inflation system is available on the Offshore, Coastal and Inshore lifejacket models

UML Mark 5i Lifejacket Inflation System:

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The UML Mark 5i Lifejacket inflation system has recently been introduced to TeamO's lifejacket range when we launched the Coastal BackTow Lifejacket. It is currently available in the Coastal lifejacket model and will also be used in the Inshore and Micro models which will be launched in the next few weeks. 

The UML Mark 5i firing head works on the same premise as the ProSensor Elite system described above. Water enters the black unit at the bottom of the firing head (see diagram above) where it encounters a paper pellet holding a spring in place. The water dissolved the paper pellet (usually within 3 seconds of immersion) and once this happens it fires a pin inside the casing which punctures the CO2 cylinder and triggers the lifejacket inflation. The firing head is protected from water by the lifejacket cover so it is unlikely that rain or accidental water splashes will accidentally trigger the lifejacket inflation. 

There is also a plastic pull toggle on the side of the firing head. This is a safeguard in case the sailor wants to manually override the system and inflate the lifejacket at will. With a hard tug on the toggle the firing system can be activated and the lifejacket will inflate. 

The UML Mark 5i firing head has a 3 year expiry date on it and TeamO advises that all sailors check the date of the capsule before going sailing. The expiry date of the UML Mark 5i lifejacket system can be found printed on the side of the black plastic cap. For pre-sailing checks we recommend you check the indicator status on the UML Mark 5i firing head. As shown below, if the system is armed and ready for use there is a green coloured mark on the firing head unit. If the lifejacket has been inflated and/or the firing head is inactive the mark will show red instead. If you see this red mark this means you need to check the Co2 cylinder and the black cap - they may need replacing. To check this, please follow the same instructions as above for the ProSensor Elite. 

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To conclude, we're including a simple infographic below to show which TeamO lifejacket model carries which inflation system.

Still have questions about which inflation system is best suited for your lifejacket? Drop us an email with details about your sailing plans and we can help advise which option would be best for you: info@teamomarine.com


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Latest Reviews

We let our customers speak for us:

80 reviews
Great jackets, unreliable customer service

It is unfortunate that my experience with Teamomarine has been marred by poor communication since I started the process in May and the product was finally delivered in July. It's frustrating when emails go without a response, the phone was never answered and it was a constant push to find out what was happening to my order. I understand there are current supply issues but a short email or text can reassure a customer that they have not been forgotten.
The products, however, are first rate, which is why I stuck with the process. A unique design and quality, I hope I never to have to use them in anger.

Dear Alasdair,

Thanks for your feedback. We will reply by email as well, but we wanted to publicly apologise for the slow communication that you experienced during your order. We have made no secret of the fact that production has been incredibly difficult this year, with several of our suppliers either entirely closed or running with long delays on parts which has affected our own UK manufacturing hub. We have done our best to keep communicating that so that customers are kept up to date, but in one or two cases emails have been missed or left unanswered, which is my bad. I can understand why this has created frustration and confusion about the status of your order. Since July we have welcomed a new team member to the business and are implementing new customer service systems so we are working to prevent this happening in future. Thank you for sticking with us, I am so glad to hear that the product meets your expectations. If there is anything else we can help with please don't hesitate to get in touch with me.

Best wishes,


Comfortable & gives sense do security

This is my third life jackets and could
Say one of the most comfortable
I had, easy to put on and off and has flat back so I can do my yoga posture while
Wearing it ! I have not tried it in the water yet and hope that I have never experience it but the sense of security and safety keeps me happy . I also like the new blue / turquoise colour as my husband has blue /royal blue which was previous edition so we don’t have problem picking the ‘wrong ‘ one as each is adjusted to personal body shape. Will Definitely recommend it !

Excellent product

I'm really pleased with this lifejacket (170N offshore). It's very comfortable, and a doddle to adjust from hot-and-sunny-summer-sailing to full oilskins. It's also easy to open up and check over. I absolutely love the concept of the back-tow harness - a genuinely brilliant idea which really could actually make the difference between life and death; especially if you do much single- or short-handed sailing, why would you have anything else? I also love the fact that they're a proper, honest-to-goodness UK-made product made by people who sail. Highly recommended.

Muy buena calidad de producto y servicio

Todo perfecto, producto de buena calidad y servicio fiable. Debido al brexit hay que pagar los costes de aduana e impuestos cuando te entregan el paquete. He podido colocar en el interior una baliza personal PLB1 Rescueme de Onesignal, aunque no pude fijarla en el soplador por falta de espacio. Por otro lado el chaleco es muy ligero, confortable y en dias calurosos se soporta bién.

Great lifejacket

Got two of these recently in different colours and got to wear them on a few coastal passages. The jackets are very comfortable, almost to the point of not noticing you are wearing one - and no more neck pain, which is fantastic. They appear very well made, look great and so far have served us well, hopefully will continue doing so in an actual emergency, should one occur. The only small gripe I have is the little loop for hanging the jacket up digging into my back - I'll probably just cut it off as I hang the jacket by the harness attachment point (much wider). Highly recommended product overall, thank you TeamO for all the incredible work I'm sure you had to do to get these on the market.