Boats with an inflatable bottom

Flat and inflatable (NDND)

— low pressure inflatable bottom (LPND) having a flat shape.

The advantages of flat bottoms (both tension and inflatable) are simplicity, low cost, minimal draft (which is very convenient in shallow water) and the ability to easily go on planing. On the other hand, such bottoms are noticeably inferior to keel bottoms in terms of directional stability, besides, they are not able to “cut the wave”, which is why the shocks of the waves are felt more strongly (especially at speed). Therefore, flat-bottomed boats are intended mainly for shallow water and low speeds.

Specifically, NDND are considered more advanced and comfortable than stretch bottoms. They are quite rigid, thanks to which they can be used without special coatings, and at the same time elastic, thanks to which they are able to dampen wave shocks to a certain extent. In addition, an additional inflatable compartment increases buoyancy and carrying capacity. On the other hand, inflatable bottoms are more complex, expensive, and more susceptible to damage than tension bottoms.