Seago is a well known name amongst marine safety gear. We see it on safety tethers and harnesses as well as a range of lifejackets. The Seago 3Dynamic looks like a smart lifejacket but is it all for show or does it perform where it matters most?

Product Overview

Overall rating:



  • Looks smart and generally well sculpted to form fit. The bladder has a crossover design to stop waves funnelling into your face.


  • really difficult to re-pack after inflation/re-arming. Poorly designed sprayhood. Light poorly positioned, might be a bit snug on larger people


Seago 3Dynamic lifejacket – tested

Seago 3Dynamic 190N lifejacket

Dry Testing

Toby comments from, shore side testing of the Seago 3Dynamic, “the sprayhood was uncomfortable and small. The light is poorly positioned as it flops over to the side. It’s easy to reach to top up with the inflation tube. Stowage for the whistle wasn’t intuitive and I had to have a look for it. There’s no pocket for the plb. It would have to be stowed on a belt.”

Our testers all liked how this lifejacket looked when worn. It isn’t too showy or flashy. It looks purposeful. They liked the double crotch strap, though as this provides a stable lifejaacket when in the water, but it is another item to be fastened or left dangling around if forgotten when putting this on half a sleep on a night watch.

Our testers found it nigh on impossible to get the window and the trigger mechanism to align after repacking. There must be a simpler way of repacking this lifejacket than with the little patch of grey material flapping around.

The casing has a pocket for a knife or small item, but it is too small to fit any of our sample plb or ais model units.

All of the testers agreed that the closure buckle on this is fiddly. It is certainly secure once fastened but fitting the metal tab through the narrow slot in the dark in a heavy seaway with gloves on will be tricky for even the best of us.

Pool Testing

Mike comments from the pool test: “it was slow to inflate and it didn’t rotate me. I could hear the air filling but it ran out of breath. It was very comfortable once inflated. It’s well provisioned with kit. The sprayhood isn’t as robust when on and I would have wanted elastic bands over the bladder – it didn’t provide much separation from my airway. Perhaps this isn’t so appropriate for larger people as it was snug on me and I’m small.”

The bladder has the crossover style which helps to avoid waves funneling to the face. The basic essentials were easy to find.

Seago 3Dynamic 190N lifejacket

Price from £149.99

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How our lifejacket scored on average out of 10 for each of our criteria

8 – Adjust speed ease difficulty
3 – Fastening buckle ease with gloves
8 – Comfort women body size (when tested by men 4)
7 – Practicality. bulk snagging
8 – Manual inflated view and fitment
3 – Sprayhood
3 – PLB fitment
5 – Positioning of essential items
5 – Night view / reflectors / light (if fitted)
7 – Ease of checking bottle / trigger status
3 – Unpacking / repacking
8 – Style
6 – In water score (due to being tested alongside other higher spec models)

62% Total as a percentage


The Seago 3Dynamic looks to offer so much on paper but in practice we found it had one too many compromises for our tastes. It is comfortable, but repacking is a real faff. the buckle was fiddly and the sprayhood was subpar. A little more thought into the layout and praqcticalities of this lifejacket could turn it around though to be a solid contender.

With thanks to

western maritime training logo

Note: all of our lifejackets tested conform to either  ISO 12402-3 (coastal/non harness) or ISO 12401 (harness versions), and this means that they all meet the basic safety standards you would expect from a lifejacket.
In order to conduct unbiased testing, our test team were given full freedom to test and evaluate the lifejackets presented to them on the tests days. Their opinions are made in a professional capacity and skippers and end users of the products and are a result of direct hands on experience. This does not override any official safety rating or certification.
legal disclaimer is available here

To read about more lifejackets go to our Best Lifejackets for Boaters and Sailors – Tested Buyers guide where you can find individual reviews for 15 current lifejackets