How Inflatable Paddle Board Technology Changed the SUP Industry
Who would have thought that inflatable stand up paddle boards would have changed the SUP market so dramatically? In this article we go in depth on the technical advances that give inflatable SUPs 90 percent of the rigidity of a hard paddle board.
Paddle boarding as a sport and leisure activity is still in its infancy. The origins of SUP actually go back millenia although the current paddle boarding movement has very clear origins in the 20th century. The beach boys of Waikiki of the 1940's and 1950's can be considered the godfathers of modern SUP as they taught surfing from a SUP. Big wave surfers like Laird Hamilton are credited with reviving the sport in the mid 1990's.
Paddle boarding is highly addictive but many who enjoyed it could only rent SUP boards because they didn't have room in their apartment or condo to store a board that was 10 to 12 feet long and close to 3 feet wide. Much like a kayak, the stand up paddle board was also a bit of a beast to transport. Inflatable stand up paddle boards changed the game quite dramatically because of the technology gains that they have picked over the last few years.
Rigid paddle boards were the industry standard
Since SUP came directly out of the surfing industry, hard boards were the only choice in the early 2000's. These SUP boards started with a block of EPS foam (basically styrofoam) that were cut by a CDC machine into something resembling a SUP shape. The foam was then hand shaped with a sander to remove the angled edges.
The EPS foam was then covered with layers of fiberglass and epoxy resin to make them more rigid and to protect them somewhat. At Glide SUP, we made our reputation as an ultra durable SUP manufacturer by applying a polymer that is used by our Department of Defense on our submarines. This thin layer of polymer allowed our SUP boards to absorb 600 times the abuse of an epoxy board.
Early inflatable stand up paddle boards
We saw the earliest inflatable paddle boards come to market around 2007 and 2008. Most of the construction used by these boards consisted of a single layer of PVC. These early SUP boards also used a drop stitch core.
Drop stitch in this case refers to the wide array of strings that attach the top layer of PVC to the bottom layer. These early SUP boards used a knitted drop stitch construction which meant that there was a fair amount of space between the strings. This extra space combined with the single layer of PVC made these boards more of a pool toy than viable paddling gear.
Many an inflatable paddle board still uses this antiquated technology. A tell tale sign that it makes up the innards of your board (since you probably don't want to cut your SUP open), is that you can only inflate the board to 15 PSI or less.
These boards were prone to "tacoing" which meant the nose and tail would lift out of the water while a paddler stood in the middle of the SUP board. A board that tacos gives a very unsatisfactory experience in the water.
An easy rule-of-thumb to figure out the quality of the board construction is the higher the PSI, the better. Make sure that the board has a PSI of at least 18 with 25 being preferable when properly inflated. This doesn't mean that you have to pump your SUP up to this level every time, it means that your board will be a lot more stable even when pumped up to a lower PSI. It also demonstrates that the top paddle board brands are more confident on the inner workings of their inflatable paddle boards.
Inflatable paddle boards improve over time
Even entry level boards that sag are not going to be worth the money to buy them. Most beginners are going to improve quicker on a sturdy board.
Part of the evolution to a higher quality SUP board is that manufacturers began gluing a second layer of military grade pvc to the original layer which helped stiffen the boards up somewhat. Some would even add strips of material, which they branded as "stringers" to assist with the stiffness. These additions increased the weight of the SUP boards but did very level to minimize the springiness of them. The drop stitch core was the reason for this because the construction wasn't tight enough to add to the rigidity of the board.
Gluing the two PVC layers added additional weight but it also increased the likelihood to bubbles would develop between the layers. Some of these bubbling boards would get pretty unsightly.
Rather than gluing layers of PVC together, the top paddle board brands began fusing the layers of military grade pvc together. Not only did this make for a lighter, less messy board, it made for a stronger more rigid SUP board.
The biggest difference maker in the new inflatable stand up paddle board technology was the introduction of a woven drop stitch core. Weaving the core rather than knitting it left far less room for air so the board was naturally much stiffer.
The devil is in the details when if comes to the specifications of inflatables. Production specs for the woven drop stitch worked out to be 3300g/per square meter with the quantities of thread being 144pcs/per square decimeter. These kind of specs mean you have invested in a very sturdy paddle board core.
Counting the drop stitches
Since you can't see inside your inflatable paddle board, one way to get an idea of what kind of drop stitch technology is inside the inflatable board, is to look at the dimples at the bottom of the board. The closer the dimples are, the greater the density of the drop stitch which means a sturdier core.
Inflatable SUP boards whose dimples are farther apart probably are using a linear drop stitch technology in which every thin drop stitch thread is parallel to the one next to it. This is far and away the most inexpensive technology available.
Dimples that are closer together indicate a much tighter V-Weave technology. Inflatable paddleboards that use this kind of weave tend to have 90 percent of the stiffness of a hard stand up paddle board.
Board plan shapes
The plan shape refers to the outline of your inflatable SUP. Top brands of paddle boards will have a flowing plan shape as opposed to blocky, angled rails and a squared off tail. In essence, they will have more of the plan shape of a rigid paddle board. A pointed nose on a touring board is fine but the rest of the board should be free-flowing.
Affordable boards tend to have a plan shape that is quite flat on the bottom. The reason for that is that creating the curves that make inflatable SUPs maneuver better in the water is a laborious and expensive process.
We're not referring to that chair your grandma likes to sit in or your long haired neighbor who listens to head-banger music. Rocker in inflatable paddleboards refers to the curve at the bottom of the board. Picture a banana for an exaggerated version of the rocker line of inflatable SUP boards.
There are a couple of ways to increase rocker in an all around inflatable sup. The first method is to shorten the drop stitch threads. This is the cheap way to create rocker as the nose will naturally turn up onces the board is inflated.
Top brands use a more expensive and more effective means of creating rocker. When they are fusing the layers of PVC together, they are able to fuse the nose and tail under pressure so that it turns them up. This creates a more subtle and natural rocker which will make your paddling experience far better.
The less rocker your stand up paddle board has, the more speed it will have. However, a flat bottomed SUP is much more challenging to turn because of the lack of rocker.
The sides of your inflatable board are known as the rails and how they are finished is a great indication of how the board is built. This is because the rails take most of the abuse that inflatable SUP boards absorb. Because you pull your paddle right alongside them they tend to take a lot of paddle strikes and get pretty scraped up.
A "Woosung Rail" is obvious as it is indicated by a line of tape that runs along the top and bottom halves of the rails. This means that the manufacturer took the cheap and dirty way of protecting the rail by just throwing some tape onto it. More on this on our section detailing how iSUPs are manufactured below.
A properly reinforced rail is one where the PVC on the top and bottom have been brought together more elegantly to create a more rounded rail. These rails tend to have several layers of tape as reinforcement.
As mentioned previously the max air pressure of a paddle board is a huge indicator of how much an inflatable stand up paddle board manufacturer stands behind their brand. If a SUP brand has a maximum of 15 PSI on their paddle board, you can be assured that they don't completely trust the integrity of their boards.
You can also bet that your inflatable stand up paddle board isn't going to be as rigid as you would like to have a fun padding experience. Most expert advice holds that having a max PSI of 20 to 25 will allow you to pump your board up to a lower PSI (like 15) and have a far more enjoyable experience than someone would on a board that maxes out at 15 PSI.
Deck pads are one area where lesser brands will try to save money as a quality deck pad isn't cheap. A premium, UV stable, brushed EVA deck pads that cover the full length of the boards and are not screen printed show a commitment to quality. A die-cut EVA pad ensures that the colors stay true and will not wear off like screen-printed deck pads tend to do.
Be careful buying a SUP brand that has grip nodules on the deck pad as they can become quite uncomfortable for your feet during a long paddle session. Look for a smooth deck pad that has a little give to it.
If you plan on taking your SUP surfing, you will want to make sure that the deck pad extends to the nose and tail. If you have ever watched any kind of surfing on long surf boards, you have probably noticed that they put one foot back on the tail to turn the board and often walk up to the nose to help them speed up.
You typically don't need a fancy fin setup on an inflatable paddle board. We do recommend that you search out manufacturers that offer a U.S. fin box as you won't be beholden to that inflatable paddle board manufacturer if you lose or break a fin.
If you are mainly going to paddle your board in flat water, a center fin setup is really all you need. Some manufacturers will include built in or replaceable side fins but these can be overkill for inflatable paddle boards.
Top brands of inflatable SUPs will have multiple attachment points also known as "d rings" where you can store your SUP accessories in dry bags as well as your PFD is you choose to carry it rather than wear it. The d rings are particularly handy when you need to carry a lot of gear for an overnight expedition.
Paddle board length is determined by two components, the size of the paddler and the use of the paddle board. A mid-sized board of 10-11 feet long is a good beginner friendly size, especially for use in flat water.
A shorter SUP of 9 feet or so is recommended for surfing or whitewater paddling as you need maneuverability in rougher waters. A 12-14 foot board is great for touring especially if you plan on having multiple riders on the board. They are a great size for ferrying kids around.
Inflatable SUP thickness
Most inflatable SUPs run between 4-6 inches in thickness. A 6 inch thick inflatable board will give you the least bend in the board. It makes the board slightly less maneuverable but we've always found less tacoing to be the goal.
Be especially careful if your inflatable stand up paddle board is offered in a 29 inch width as most of the cheap drop stitch cloth on the market is produced in that width. 29 inches is not a wide platform by any stretch of the imagination and you will more likely have issues with weight capacity. A stand up paddle board that narrow will surely test your balance as it will be very unstable.
Paddles and such
Most inflatable stand up paddle boards come with a 3 piece paddle, among other accessories. A three piece paddle fits nicely in the transport backpack that should come with your inflatable board as well. You can always upgrade your paddle via the many brands that specialize in paddles.
SUP paddles come in a wide array of options these days. You can order paddles in various shapes and colors. Whether you want a purple or a red paddle to match your red paddle board, there is an option for you.
Some other accessories that should be included with your board are a hand pump, leash, fin, carry strap and kayak seat. Most kayak seats are no included with the purchase of your SUP board but a couple of the better brands include them. Check the fine print at whatever store or site that you buy your inflatable SUP from to make sure you have all the details around what is included with your board.
Keep in mind that some brands include add ons, while others charge for them. Be careful of all the "great deals" out there.
The inflatable SUP manufacturing process
The inflatable stand up paddle board manufacturing process varies quite a bit by manufacturer. Some brands are still cutting out PVC panels by hand which can lead to inconsistencies in the size and shape of each paddle board.
There are a few SUP brands that manufacture their paddle boards in state-of-the-art factories that use automation to cut the panels and seal them up. Most of the cheaper brands pay workers to cut the panels and sew them together on work benches. This old school approach can lead to dust and contaminants getting inside of the SUP board. It also leads to very inconsistent board quality.
Working with drop stitch technology
The manufacturing of the drop stitch that makes up the core of an inflatable stand up paddle board is a very slow process. Drop stitch machines crank out the fabric a few centimeters every minute which is the reason drop stitch is a fairly expensive material.
Drop stitch material is produced in several thicknesses. How long the threads are in the drop stitch are determines how thick the inflatable stand up paddle board will be. As mentioned above, threads that are merely parallel to each other make up "linear technology" drop stitch material which is a less robust way of tying the upper layer of PVC to the bottom of the board.
Linear drop stitch technology is much cheaper to produce than the V-Weave Technology that the higher end inflatables use. The non-linear technology of the V-Weave allows for more threads per square inch which makes for a much stronger inflatable SUP which can handle more weight capacity whether you are using your SUP in flat water or rougher waters.
Expert advice concludes that the thicker your inflatable SUP is the more stable it will be. A stand up paddle board that is 5 inches thick will be 40 percent more rigid than a board that is 4 inches thick. This just goes to show that the "best deal" for an inflatable SUP probably won't necessarily get you a board that is well suited for your paddling needs and weight capacity.
Keep in mind that even though there are thousands of tiny strings that make up a drop stitch core, each one is extremely thin. This is why your paddle board looks completely flat when it's deflated.
Breaking down the technology used in inflatable SUP rails
As mentioned above, the "Woosung Rail" is simply a rail that has been taped onto the side of the stand up paddle board. To picture this, envision the layer of PVC that makes up the top of the SUP and the bottom layer having a space that is several inches wide keeping them apart. That gap is then filled by another strip of PVC so two seams are created on the rails.
Many stand up paddle boards are built using this technology which means that the portion of the SUP board that takes the most abuse from paddle strikes, etc., is protected by only a singer layer of PVC.
The "Leewards Rail" is basically a beefed up version of the Woosung Rail. By "beefed up" we mean that a whopping 2nd layer of PVC has been added to it. The problem here is that you still have 2 seams on each side of the stand up paddle board that you are trying to hold together with minimal PVC.
The "Infla Rail" is used by top brands as it gives the most strength to the paddle board rails. On an Infla Rail, the layer of PVC that makes up the top of the paddle board meets the bottom layer of PVC so that there is no gap between them creating a single seam. Another layer of PVC is welded to the seam which gives the rails 4 layers of PVC protection.
Since the rails create the most likely spot that inflatables will leak from, the Infla Rail method rules supreme in creating an ultra durable stand up paddle board. With the Woosung and Leewards construction methods, you are testing out the durability of the two side seams every time you put air into your paddle boards. Discovering a leaky seam while out paddle boarding could prove to be catastrophic!
Deep dive into the 3 types of builds of inflatable paddle boards
In the quest to offer more deals and new releases of paddle boards, many brands will gloss over the type of technology their SUP features. We'll now cover all the other details that they leave out in order to make you a well informed consumer.
Single layer technology
Single Layer Technology is the most common assembly method for cheap SUP brands. We've already discussed how drop stitch makes up the internal core of the SUP board but drop stitch fabric by itself isn't airtight, so then a liquid PVC layer covers the drop stitch which, once dry, creates an airtight seal. This is the single layer.
There are two main advantages to single layer boards: weight and price. Less material makes for a very lightweight paddle board and less cost to the manufacturer gets passed on to the consumer. This manufacturing method creates a board that has a slightly lower maximum weight than the stringer or laminated versions that we'll discuss next. Inflatables using this technology appear to be a relative bargain however you are likely to have a board that doesn't hold up for the long haul and will taco which will impact you paddling experience significantly. Many brands that use this manufacturing process will tend to be quite vague about their technology's features on their site.
Those that are familiar with early rigid SUP board or even surfboard construction know that the stringer referred to a piece of wood that was laminated in between the two halves of EPS foam and ran the entire length of the board. The concept was that the "stringer" made the board even more rigid.
With inflatable paddle boards, brands that utilize single layer construction create a stringer out of a strip of PVC that they glue to the center of the board from tail to nose. The PVC stringer gives these single layered boards a bit less flex and doesn't add a whole lot of weight because it's a pretty narrow strip. That being said, it's a bit like putting lipstick on a pig as there is only so much rigidity that a strip of PVC will add compared to boards that utilize multi layer technology.
Fusion multilayer build
The laminated multilayer build is the premium technology in the inflatable stand up paddle board manufacturing process. Because glue is not used to bind the multiple layers of PVC together, there are no longer cosmetic wrinkles or bubbles on the surface of the board.
More impressively: these inflatable SUPs are 20-25% lighter and 25-30% stiffer than those using a glued multilayer technology. The tech shaves roughly 5 pounds off the weight of the SUP which is a massive savings! Initially the cost of these boards was quite a bit higher than the single layer or stringer boards but we've seen the prices come down as demand has increased.
If the site or store that you are looking at for your SUP, talks mainly about the accessories that come with their stand up paddle boards rather than the technology that's inside them, that is a good indication that they only carry single layer boards. Do your homework to make sure that you end up with a SUP that paddles well and will give you many years of use from it.
Inflatable SUP accessories
We touched on accessories in the "Paddles and such" paragraph but we'll take a deeper dive here as many of the cheaper brands will not only try and sell you a single layer inflatable paddle board but will also include some subpar accessories. Some of the gear that is included under accessories, can make the difference between an adequate and a fabulous paddling experience.
Paddle, travel bag and hand pump
A 3 piece paddle is a must with your inflatable SUP because one of the great benefits of inflatables is how portable they are. The last thing you would want is a paddle that didn't fit nicely in your SUP backpack and you had to carry it by hand.
Some other nice features on a 3 piece paddle are an 11 percent bend in the blade so that you can do more paddling on each side of your SUP without it turning. A blade made out of reinforced ABS and a fiberglass shaft will hold up to quite a bit of abuse. You also want to be sure that your paddle floats as no one wants to dive to the bottom of a lake to find their SUP paddle!
One of our favorite accessories to carry your inflatable SUP as well as your other gear as you hike into your favorite waterway is a travel backpack. The best travel backpacks that we've found are made with reinforced nylon and have travel wheels so that your kids can help with SUP transport.
One of the accessories that brands will tend to skimp on is the pump. They do this by providing a single action pump. If you plan on sticking with a hand pump to inflate your SUP as opposed to an electric pump, by all means make sure your SUP comes with a dual action pump.
One of our favorite features of the dual action pump is that it pumps air into your SUP as you push down on the handle as well as when you pull the handle back up. As you get to around 12-15 PSI, you can then switch the pump to single pump mode to force the last remaining bit of air into the paddle board. This is another activity that we highly recommend you teach your kids to perform.
All that being said, once you have had your inflatable paddle board for a while, you will probably want to invest in an electric pump. With an electric pump, you can set the exact PSI that you want to pump your SUP board up to and the pump will stop when it reaches that PSI. It is a truly idiot-proof system.
Electric SUP pumps are typically powered by the lighter port in your vehicle. Most of them also offer an optional battery which you can use to power the electric pump when you are away from your vehicle.
Other cool add ons
Paddle boards feature the unique ability to save your life. We all know that we have to carry a personal flotation device (PFD) with us when we are on a SUP per the US Coast Guard but what good does that PFD do for you if it's strapped under the bungees on your board after you have fallen in and your SUP is blown away from you? Think of your paddle board as one big PFD that is always nearby as long as you are wearing your leash.
Early inflatable SUP boards had fins that were molded on. This is really not an ideal scenario, as fins tend to catch on rocks or underwater tree branches and if you break one that is not removable from the board, the SUP will become useless to you.
Some SUP brands have fin boxes on their boards that only accommodate their fins. During the pandemic, fins have been in short supply so if your SUP brand is out of them you will be up a creek without a fin (see what I did there?). Look for a manufacturer that features a US fin box to house the center fin so that you can use fins from any independent fin maker.
One of the more important things to be included in a SUP repair kit is a wrench like tool that lets the user tighten up the air valve from time to time as they inevitably will come loose and cause air to leak from the board. The patching kit comes in handy as well should you puncture your SUP.
One of our favorite features of the inflatable SUP is the ability to add a kayak seat that attaches to to d rings on the paddle board. The kayak seat is a great way to let kids try your SUP for the first time as there is very little skill involved in sitting while paddling. Most SUP brands charge $100 or more for a kayak seat but there are some that include it with purchase of the board itself.
Many SUP brands charge around $30 for a carrying strap that attaches to the d rings on the SUP and lets you carry your board with the strap over your shoulder. There are one or two paddle board brands that actually included the strap as well. It can be quite convenient if you need to schlep your board a ways to the water as your hand will often fatigue after several yards.
When paddle boards first came on the scene, their popularity became the stuff of legends. The new sport was billed in most circles as the "fastest growing water sport in the world". Hard SUP boards were the only technology that existed which proved problematic for the millions of people of lived in apartments or condos with limited space.
Inflatable technology seemed like a logical alternative to the ubiquitous hard SUPs. The biggest question for the early inflatable paddle board inventors was "how do you make a board that is filled with air as sturdy as a board that is made with solid materials?"
After much trial and error with single layer SUPs that had linear drop stitch technology, those board builders stumbled upon a better way. It was determined that by fusing together multiple layers of military grade PVC, the not only could create an outer shell of a SUP board that was quite rigid, they could also craft if so it had a rocker that was very similar to a hard board. By then adjusting the legacy knitted drop stitch technology of the inner core of that board to a woven drop stitch, they were able to create a SUP that was 90 percent as rigid as a hard board.
These advances in technology created a boom in paddle board sales as anyone that had limited storage space or weren't able to move a large SUP board on the roof of their car could now participate in the SUP lifestyle. The next time you are at your favorite waterway, take a look at the SUPs you see, we can almost guarantee that most of them will be inflatables.