Water Sports

Wireless Thermalution – Yellow Grade Plus

4.55 out of 5 based on 20 customer ratings
(20 customer reviews )


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The Thermalution® Yellow Grade Power Heated Undersuit is designed with both the wetsuit scuba diver and dry suit scuba diver in mind.  Using a wireless controller the Thermalution Yellow Grade Plus enables a diver to change the temperature of their drysuit during a scuba dive without having to break the seal of the dry suit.

To give divers longer battery life, Thermalution has powered the Yellow Grade suit with two high capacity, 7.4 Volt, rechargeable lithium-polymer batteries. When fully charged the batteries will provide heat for up to 4 hours.  These batteries are around 1 inch thick.

Note:  The Thermalution suit is designed to get warm enough to heat even the coldest of water entering a wet suit.  When diving dry vs a wetsuit, the heat will feel much warmer on the skin.  Most drysuit divers wear a thin layer beneath the Thermalution when diving in a drysuit, due to the large amount of warmth produced even on the low setting.  These scuba divers are then able to utilize a warmer temperature setting without overheating the skin on their back.

Thermalution® is by far the best heated wetsuit product available on the market!  It uses a non-metallic heating panel, positioned on the back to warm up your core area.  With a weight of only 2-3 lbs, it is worn virtually unoticed beneath your wetsuit or drysuit.  Of all heated wetsuit products currently available, Thermalution® has the capacity to heat up in the shortest amount of time (under a minute).

Thermalution® uses Far Infrared Ray technology, which doesn’t just heat your skin like many other products.  Thermalution® actually heats deep within your core, giving you improved blood circulation, enhanced cell and tissue regeneration, pain relief, and comfort to the entire body.  You will be amazed at how much more comfortable you will feel after turning on the suit to even only the lowest of three settings.  Once you have a dive in a Thermalution, you won’t ever want to venture out on a winter day without one!

20 reviews for Wireless Thermalution – Yellow Grade Plus

4.55 out of 5 stars

  1. Reviewer profile image
    5 out of 5

    Rich Hopkins

    My wife and I are both scuba instructors in Oregon. I started diving with my Yellow Grade a year ago today. I wanted to wait to do a review until I'd logged a few dives so that I could give an honest, informed review of the product. If you're like me and don't like reading lengthy reviews here is the bottom line: 66 cold water dives of toasty goodness.

    Read on for details and some tips and tricks to get the most out of your Yellow Grade heated shirt.

    Before I get into the product itself, I want to talk a bit about the folks at HeatedWetsuits.com. When I first saw the Thermalution ad in a diving magazine I tried contacting the company directly. The company, based overseas, directed me to Matt Patton at HeatedWetsuits.com. While these guys appeared to have been around a while in the surfing industry, I'd never heard of them in the scuba world. I contacted Matt and was immediately struck by his professionalism, honesty, and willingness to work with me.

    I got my wife one of the early models of the 15M Surf Series shirts and we took a couple of tropical trips. My wife gets pretty cold, so typically, even in tropical waters, she could only do about two dives a day. With the heated shirt, we were doing five dives a day for a week! This product simply transformed our diving experience. Then, my wife started using it in her dry suit and loved it. The only down side was that she couldn't change the temperature during a dive because the wired controller had to be tucked inside her drysuit.

    In all honesty, the first models had some design flaws. Specifically, the battery connecters were difficult to put together and they were susceptible to breakage and salt water corrosion. I contacted Matt about these issues and he went above and beyond to fix the problems.

    Eventually my wife and I started teaching scuba and spending more and more time in cold water. I noticed my friends were starting to use heating systems in their drysuits that cost them some big money. These systems had canisters that attached to their scuba cylinders with wires that went through the inflater valves of their drysuits and switches that had to be activated to turn on the heat. Based on what my friends had to say, it seems that these systems were okay, but expensive, and much like the first generation of the Thermalution shirts, they needed some work to be ready for the real world (and still do in my opinion.)

    When the Yellow Grade became available my wife and I decided to give them a try. By now Thermalution had solved the battery connector issues and the controller became wireless. I called Matt and he remembered me. He answered all of my questions and took my order.

    We logged our first dives with the Yellow Grade shirts on March 2nd, 2013. Immediately I knew I'd made a good decision. It wasn't too cold that day, (49 degrees in the water and 46 degrees outside) but it sure felt nice to be warm. Since then we have taken our shirts with us on dives all over the world; both cold and warm water diving. (Incidentally, no airport issues with the shirts or batteries.)

    Here in Oregon we dive in temperatures ranging from the mid 30's to the low 70's depending on the location and time of year. Typically, the air temperature is lower than the water temperature. So the Yellow Grade not only keep us warm during our dives, but between dives as well.

    In tropical waters I tended to only actually use the heater during night dives, but my wife used hers during the dives, between dives, and during long boat rides. A set of batteries lasted just fine on 3 tank boat dives. We have also become "the Most Interesting Divers on the Boat" as many warm water divemasters take great interest in the shirts - a great way to keep from being left behind by the boat at the end of the day btw! ;).

    Over the past year my wife and I have had zero problems with our Yellow Grade shirts. They have worked flawlessly. We have also learned a few tips and tricks that I can pass along...

    1. Put your wireless controller on a retractable lanyard and attach it to your BCD. The shirt has a disc that sits in the middle of your lower back that is used for communicating with the controller. When you change the temperature settings with the remote the disc vibrates to give you feedback. I find I can change the temperature setting much easier, if the controller is closer to the disc. Also, this way, I don't have to worry about strapping yet another thing on my wrist (I already use a wrist mounted computer). The added benefit is that I can easily change the temperature with one hand.

    2. Get a second set of batteries. If you're like me and want to dive, dive, dive, during a dive trip or dive weekend, a second set of batteries is essential. Start the day with both sets charged and you will have plenty of power for the full day. When one set needs recharged, you'll have another set ready to go and your diving won't be interrupted nor will you have to be cold. Which leads me to my next suggestion...

    3. The batteries are pretty thick. If you have a small, thin, frame (like my wife) they can make the sides of your rib cage a bit sore after several hours/days of use. It turns out the smaller (cheaper) batteries for the 15M and 70M shirts also work with the Yellow Grade. These batteries don't last as long, but they are much thinner and my wife doesn't have the same issues with them bothering her ribs like the thicker batteries.

    4. The disc in the back of the shirt is also troublesome for small, thin, divers. My wife's cylinder rests right on the disc, which then puts pressure on her lower back, giving her a sore back after hours/days of diving. The simple solution is to wear the Yellow Grade over other undergarments while diving dry, adding extra padding. You will stay just as toasty. When diving wet a small bit of neoprene padding will do the trick just as well.

    5. Coat the battery connectors in underwater camera o-ring grease. This doesn't cause any issues with the electrical flow and will totally prohibit corrosion when diving wet.

    6. Be sure to rinse the wireless controller with fresh water after diving. If you don't, the slide switch can get a bit sticky. Nothing a good fresh water rinse and some o-ring grease won't fix though.

    7. Turn the controller to the off position after you're done. The controller has a small LED that flashes periodically, using different colors depending on your temperature setting. If you run the batteries all the way down, the controller will continue to blink. There is no obvious way to replace the controller batteries. I assume they last quite a long time, but by ensuring the controller is off when the shirt isn't in use, they will last that much longer.

    Hopefully this review has been helpful. If you're a serious diver (in either cold or warm water) you can't go wrong with this product. Just like any other dive equipment, take care of it and it will take care of you.

    Happy (warm) diving!

    Rich H. from Oregon

    15 of 15 found this helpful
  2. Reviewer profile image
    5 out of 5

    San Diego Diver

    Fantastic service in getting my 2nd vest shipped directly from the manufacturer. Very pleased with this item, first one lasted about 4 years with heavy use. For this one, I asked a tailor to add a plastic front zipper to reduce wear and tear on the wiring when donning/ doffing.

    2 of 2 found this helpful
  3. Reviewer profile image
    3 out of 5

    Elliot Royce

    Customers should be aware that if you lose the remote controller, the distributor needs to send the suit back to Taiwan (they will pay the postage) to pair another controller with it. And it will cost you $200.

    It also seems a bit underpowered. In 63 degree water in a 5mm semi-dry suit I was still chilly although nowhere near as cold as my buddies without the vest!

  4. Reviewer profile image
    4 out of 5

    Elliot Royce

    I've used this now for 3 dives on Trimix and it definitely helps a lot. Also, very nice on the boat after the dive when wet and a cool wind is blowing. My suggestions for improvement are: 1) better pockets for the batteries so they don't slip out and to make it easier to insert them (try velcro); 2) better connectors for the wires (one of mine is already about to break because they are very fiddly); and 3) offer it with an integrated hood.

  5. Reviewer profile image
    5 out of 5

    walter rosenthal

    I am a male and 50 years old and just bought one of these in a XL size and it works really well. I used it with a drysuit and the remote on the arm works great. When your underwater and click the switch once you can hear and feel the vibration on your back that it received your selection. It starts warming in about a minute or two. I wore a teeshirt under it and a sweat shirt over it in about 45 degree water in Lake Charlevoix in michigan with a 7mm drysuit in 30-60feet of water. It allowed me to stay underwater for over two hours. The heating elements are only on your central back area. I wish it would cover the front too. If I wouldn't have had this on my time underwater would have been almost cut in half. There are three settings and they are easy to use. You can shut it off if it gets to hot. I did still get cold in the end but this allowed me to double my underwater time. The batteries never ran out of juice. The batteries are under your armpits almost and over time are a little uncomfortable. but otherewise in a good location. Works great!

  6. Reviewer profile image
    5 out of 5

    Phil K

    The heated vest has been a great heat producer to keep you from getting cold during extended dives. Have worn under my wetsuit during both morning and afternoon training sessions on a single charge. Also works very well under my Drysuit to keep the chill off during 38 degree dives.

  7. Reviewer profile image
    5 out of 5

    Michael Colton

    Totally impressed at how well the Thermalution yellow grade suit performs. It made winter diving in the Red Sea much more pleasant and took us from a dry suit to a 5 mil. Suit lasted for at least 2 back to back dives before needing a recharge. The wrist controller made changing temperature settings a breeze. We should have bought them sooner!

  8. Reviewer profile image
    4 out of 5

    Lee Clark

    MUNISING 2015-
    I looked at the amount of dive gear strewn around my seat as the boat left the dock out of Munising, Michigan. Three bags consisting of a bag containing a drysuit, one bag of undergarments and one bag of dive gear. For the past three years my diving had consisted of mostly Caribbean diving, where all you need is the most basic of dive gear. But this was going to be different, just how different I was about to find out.
    “Welcome to Lake Superior diving” the dive boat captain told us. “Where it is always deep, dark, and cold.” What in the world was I doing here? Basically I am a warm water diver, among Michigan divers that think that diving in any water above freezing makes it a good day to go diving. To answer what was I doing here; we have to go back over a year to a pod cast hosted by Rich Synowiec. Rich’s show, DiverSync, is usually on Tuesday evenings on Talkshoe.com (Call ID 89155). Rich owns several dive shops in the Ann Arbor area, and is a professional dive instructor and hosts a weekly diving talk show about all things diving, usually involving dives done during the past week with students, friends, or family. Rich talks about every dive trip like it is the one last dive you have to make before you can say you have dived it all. His annual Munising trip is usually sold out nearly a year in advance, and is the start of a number of trips throughout the coming summer months.
    “Ten minutes till we anchor,” the captains voice brought me back to the present. I barely had my thick undergarments on. One foot was slipped into my drysuit and I had to stop and think, “How do the suspenders go?” “Is it inside the legs or outside the legs?” “I really wish I had tried putting this thing on a few more times before the trip,” I thought to myself. A year had passed since I had last put on a drysuit, and several years had passed prior to that last drysuit dive. As stated earlier, I was basically now a warm water diver. As the boat came to a stop and the platform dropped off the stern, the other divers were already making their way to the exit point. My wife helped stuff the hood into my drysuit. I felt like the Michelin Tire man dressed in my DUI XM450 undergarments and my DUI FLX Extreme Drysuit. As my wife helped me put on my Aqualung Black Diamond BCD, I suddenly realized that all my equipment had shrunk since the last time I had used them. “Too many burritos”, my wife commented about the lack of fit regarding my equipment as one by one the rest of the divers exited the boat. All this time Rich waited patiently as I dressed and struggled into my gear. “Suck it in” my wife said and we finally managed to buckle the last of the straps. By now it was just Rick and myself on the boat. As I waddled to the back of the boat, I jumped in and immediately felt relief as the 50 degree water cooled the outside of my suit. Soon Rich and I descended into the depths and my Lake Superior diving had begun. At around 70 feet the wreck of the Smith Moore came into view. Rich and I spent the next 20 minutes exploring and examining the wreckage of this ship. Rich took many photos of me and the other divers around the ship, all the while keeping a constant eye on me that I didn’t do anything crazy. I looked at my depth and temperature gage and 90 feet and 43.6 degrees was the depth and water temperature shown. Amazingly, I never felt cold. Thank you DUI. As the occasional twinge of cold did creep in, I activated my secret weapon, the Thermalution heated undergarment. Any feeling of cold melted away as the heat from the heated vest warmed up my core. I understand that Rich is now going to become a Thermalution dealer. It is well worth the price if while diving being cold is not your thing. Aside from the terrible instructions included with the product, the Yellow Grade heated vest works as promised. As the dive progressed, I felt large chunks of rust falling off my deep and cold water dive skills. By the end of the dive I had my buoyancy, and air consumption under reasonable control. As we started back toward the surface, I felt comfortable at our safety stop and exited the water wanting to do it again. By the end of the fourth dive the next day, I was ready for more. Maybe those Michigan cold water divers are not so crazy after all.
    Next year is Rich’s 10 year anniversary of the Munising trip and it is sure to be another sellout. While it is promoted as a camping and diving trip, my wife and I stayed less than a half mile away in the Comfort Inn. I felt it was the best of both worlds. We got to meet the other fantastic people around the campfire in the evenings; but also got a good night’s rest, minus the mosquitoes.
    In conclusion, while most divers are a generous bunch, I would be amiss if I did not give a shout out to all the people on that trip. They generously donated food, gear, bug spray, and whatever else you needed that you didn’t remember to bring. Thanks to you all, most of whom I will probably never see again, you made my wife and I feel right at home. We are especially grateful to those of you who loaned us their weapons and the ammo to exercise our second amendment rights. My wife now wants to go shooting as often as possible. If you want to take a fantastic dive trip and have the skills needed for that particular dive trip, (Rich spells out the minimum requirements of each trip on his website: www.diversinc.com) then I highly recommend you contact him for a fun and unforgettable adventure. I now hold the record for coming the longest distance for one of Rich’s trips. San Diego to Munising; but as everyone knows, records are meant to be broken.
    Lee R. Clark
    San Diego, CA

  9. Reviewer profile image
    5 out of 5

    This was a birthday present for my wife to go along with her new 5/4/3mm wetsuit. The Yellow Grade Plus fit well, was warm and the batteries charged quickly. It was easy to operate and the batteries lasted thru two dives and kept her warm in the 76 dF water.

  10. Reviewer profile image
    4 out of 5

    Marc Shargel of Living Sea Images

    I withhold the fifth star only because of some ergonomic conveniences that are lacking. The basic function is excellent, it works great under my drysuit.

    Things that could/should be improved:
    1) Batteries fall out of the battery buckets when upside down. I sewed on velcro straps to prevent it, but should be part of the product.
    2) The little holes at the bottom of the pockets are difficult to pass the plugs pass through. Should be larger or oval to match the plugs.
    3) the slider on the wireless remote is small and difficult to operate with dive gloves.

    But despite these imperfections I love this thing. I gave one as a gift for Christmas.

    BTW, if you wear it under a drysuit you will likely find it too hot, even over a T shirt. I added a permanent layer of fleece right under the heating elements. I wish the makers offered that as an option.

  11. Reviewer profile image
    3 out of 5

    Kimber Chard

    The system works well some of the time. I am having issues with the remote communicating with the vest receiver. Sometimes it is great other times I can't get it to turn on even if I put the remote right outside my dry suit in the area of the receiver.
    It can be a little frustrating.....

  12. Reviewer profile image
    3 out of 5

    I recently bought theThermalution yellow heated vest for coldwater diving andso far it it works as promised. It keeps me warm and I have had no problems with the wireless transmitter. The only thing I had a problem with were the batteries under my arms. My drysuit is the body contouring neoprene Everdry 4, and with the batteries in situ ,it is now too snug to be comfortable. I would suggest flatter batteries in the next model. I have since ordered a DUI Flex drysuit to accomodate the vest and batteries. It was an expensive correction. Best of luck with the next model, Linda

  13. Reviewer profile image
    5 out of 5

    Rich K.

    I got to try this out last weekend with two dives. It was unseasonably warm--water was 57 degrees at depth, but I thought I'd give it a try anyway.

    I was not disappointed. I initially had some difficulty figuring out if it was off or on, and which setting it was on. I finally figured out that the wireless receiver sits right under my steel tank and it sometimes blocked the signals. I began holding the wireless transmitter back towards the receiver and had no further problems. I began to just depend on the vibrations of the receiver to tell me which setting I was on. Doing that made it easy to know if it was on low, medium or high.

    I did both dives wearing a drysuit and a 200 gram undergarment. I ended up cycling the heat on and off--using just the low setting--during the hour long dive. The vest heats up VERY quickly, in a matter of seconds, and became too warm from time to time. By the end of the first dive I was pretty sure I liked the vest.

    Dive two followed after about a 1 1/2 hour SI, during which I turned on the vest for brief periods of time to see what it would be like to warm up on the surface. Nice! On the second dive, I ended up feeling colder (not unusual for me on second or third dives). I ended up leaving the vest on the low setting for the entire dive. The vest did an incredible job of keeping my core warm and toasty during the second hour-long dive. I forgot to wear socks, so my feet and hands were the only thing that were even slightly cold. Being toasty warm had two additional, unanticipated benefits; (1) I didn't feel the urge to pee from the cold, and (2) my air consumption went down.

    I cannot imagine having to use any setting but low while wearing a drysuit. I wore the vest over a T-shirt and found it comfortable on low. For the brief periods where I tried the medium and high settings, the vest quickly became way too hot. I was beginning to perspire. I'm actually thinking I might want to try it with a wetsuit now and I haven't had any desire to wear a wetsuit in over a year.

    What a great product. Well worth the money in my book.

  14. Reviewer profile image
    5 out of 5

    initial trial dive had to be aborted because of a leaking regulator, but my wife said it worked fine for the ten minutes we were in 42 degree water

  15. Reviewer profile image
    5 out of 5


    I am a Pacific NW cold water diver and looked around for a while before purchasing the Yellow Grade heated tank top. I loved the idea of it being wireless and the ability to control my heat levels during my dive. I have had the unit for a few months now and it's totally changed my winter diving. I'd be lucky to get a 45 min dive and now I have had an 84 minute dive and did not call it due to being too cold! I just wish they had heated glove inserts! The best part about this system is I can dive it wet or dry as we travel to San Diego often and dive wet most of the time there. I am VERY happy with my purchase and have had no issues with the remote on my arm communicating with the shirt even under several layers and my drysuit. Super satisfied!

  16. Reviewer profile image
    5 out of 5


    I use it for scuba diving in two different dry suits with no need connector, no need canister, use it in many wet suits, wear it for outdoor in cold weather... Love it!
    Not sure where and when to change the battery of the remote control.

  17. Reviewer profile image
    5 out of 5

    Ron Camp

    I just received my vest and tried it out for the first time last weekend. What a tremendous difference it made.
    The previous day without the vest I was quite chilled, with the vest I was very comfortable on the medium setting.
    I highly recommend the product and the company. Thank you for the great customer service

  18. Reviewer profile image
    5 out of 5

    I bought the yellow grade from Brazil when going to the US. It was there before I arrived. No worries there!
    I bought it for my girlfriend and now there is no more excuses for not diving in could waters!!! She loved it!

  19. Reviewer profile image
    5 out of 5


    Super very hot !!! Ice diving forever. With yellow grade . Fast shipping in Russia !

  20. Reviewer profile image
    5 out of 5


    I've got Reynaud's Syndrome so my hands and feet lose all circulation if I'm exposed to temp's below 75F. Now that my core stays warm, my extremities keep their circulation. I'm no longer the wuss who has to end the dive early! The wireless feature is fantastic for preventing overheating between donning gear and getting in the water and the vest warms up very quickly. It's also great for conserving battery life for either multiple dives or a nice, long CCR dive.

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Warranty Information

Petatech International Company, Ltd (Makers of Thermalution) offer a 12-month Limited Manufacturer's Warranty from the date of purchase from any retailer worldwide. This warranty covers any Defective Materials or Components and Faulty Workmanship for one year. Thermalution also offers a 6-month warranty on all batteries and components. Customers may register their Thermalution products online for a full year manufacturers warranty on the batteries as well.