The different types of construction of the inflatable paddle boards are important. The iSUP is made of dropstitch. It is the heart of the SUP inflatable. This technology consists of assembling two layers of PVC by weaving thousands of polyester or nylon threads evenly spaced. The mesh between the 2 layers (some still call them “skins”) allows to keep the flat shape of the SUP inflatable despite the pressure. This mesh is important, without it, the board would be out of shape.
A good quality dropstitch will have a denser mesh size, i.e. a smaller space between the thread and therefore more threads. The board will accept more pressure, so it can be inflated more strongly to increase its stiffness. A “normal” dropstitch inflatable paddle board inflates to 15 PSI, while a higher quality dropstitch board will be inflated with a pressure up to 25 PSI.
The dropstitch is not the only element to be taken into account when measuring the quality of a board. What surrounds it is also important. Here are the different types of construction.
iSUP: Dropstitch construction
Single layer construction
These are the most entry-level models. This does not necessarily mean that they are of poor quality, but chances are they are a little soft and less durable.
The single layer paddle is simply composed of the 2 PVC layers connected together by wires. It is important to be aware that a single-layer SUP will often have some small defects. This is the technology used in the construction of an Aqua Marina paddle.
| Main Advantage | Disadvantage |
| affordable price | Almost inevitable visual defects |
Single layer construction + stringer
The stringer is a PVC strip that is added in length to and under the inflatable board.
Its interest lies in the fact that it improves the rigidity of a single layer board. The board will also be more resistant. This technology is used in the construction of the Fanatic iSUP in its Fly range and formerly on some Zray models.
| Main advantage | Main disadvantage |
| Prices still “entry-level” | A little heavier than a single layer board |
Double layer construction
The second layer of PVC is not stretched and is glued to the PVC of a SUP single layer.
Its role is to make the board more reliable by improving the waterproofness, strength and rigidity of the board. This second layer increases the weight of the board and after a few years the glue breaks and imperfections appear on the surface. The Premium range of Zray paddles in particular has a double-layer construction.
| Main advantage | Main disadvantage |
| More rigid board | Heavier board from 2 to 3 kg |
Double layer fusion construction
The second PVC layer is no longer glued but hot fused with the first PVC layer. Two layers are fused before inflation at the factory, which allows the SUP to become even more rigid.
The “Fusion” process is effective on the entire board. It gives the SUP inflatable more rigidity and a lighter weight than the double-layer inflatable paddle due to the disappearance of the glue. The Deluxe range of Starboard paddles is built with this principle.
| Main advantage | Main disadvantage |
| Board more rigid than the glued double layer | Higher price (but which tends to decrease) |
MSL construction
This construction is registered and protected by Red Paddle. The MSL process is the same as the double layer fusion process, but a layer of unidirectional glass fibres is inserted between the two fused PVC layers. This “sandwich” method is even closer to the construction of a rigid paddle.
The stiffness is then significantly increased and above all it makes the board totally waterproof and durable. Moreover, the Red Paddle community will not change its choice in any way.
| Main advantage | Main disadvantage |
| More rigid and durable board | Higher price |
Double chamber construction
To paddle more than 300 metres from the shore (and up to 2 miles from the shore), you must be equipped with a double chamber iSUP. If you are the victim of a damage on one of the chambers, you can return to the shore without sinking. Few SUP brands have taken advantage of this technology because it is complicated to implement. Today, we mainly find the Starboard paddle and Aztron paddle brands.
| Main advantage | Main disadvantage |
| Ultra rigid and safe board | Higher price (but which tends to decrease) |
In conclusion, you will have understood that in inflatable paddle, you get value for your money. The more a board requires special production, the more its price increases but the more durable it will be.
As a reminder: when the temperature rises, the pressure rises. So if you inflated your board at 6 am and leave it in full sunlight at lunchtime, all welds and glues will be mishandled and will accelerate the deterioration of your inflatable paddle up stand.
Riding advice: the electric inflator is one of the rider's best allies.