Excellent question. The answer? Miracle "Polypropylene copolymer". The entire hull is made of this stuff! Frankly, without it there could be no folding Porta-Boat. The hinges are absolutely water tight and are so unique they have been granted international patents.
So, what exactly is Polypropylene copolymer? It's an exotic engineered resin originally developed by the U. S. Aero-Space industry. It has incredible properties. The hinges can take stress of over 90,000 pounds per square inch. They have been designed so that the higher the pressure on the hinge the more it "wants" to remain sealed. The Porta-Boat Polypropylene hinges have been modulus tested at a rate of over 500,000 openings and closings without failure. Original manufacturer DuPont (DD ) conducted tests and found the material actually became stronger after 500,000 foldings, and Sears (S) uses it in their lifetime DieHard batteries because the material is impervious to acid.
Also, our formula utilizes an ultra-violet (UV) filter. This renders the material unaffected even by exposure to saltwater. It won't even burn! This same formula is presently being used in the manufacture of the new "lifetime" batteries, automobile bumpers, bullet proof vests, Astro-turf, and even non-rusting highway road signs. How long will it last? We have inspected 25+ year old Porta-Boats and they looked almost as good as new!
That's right... the hinges and hull material have now both been time-proven for 30 years by almost 50,000 satisfied customers, worldwide! That's why we can offer our famous 10 year limited hull material warranty.
1- Flexibility: is the secret to Porta-Boat's incredible stability! This is the same reason inflatables are more stable than rigid craft. When a strong wave slams against the side of Porta-Boat's "Flexi-Hull"™, the polypropylene flexes inwards approximately 12%. This immediately dissipates the energy of thewave & actually disperses its force by over 90%. It's really almost impossible (notice we said "almost") to capsize one of these craft. Although safe boating is a matter of using common sense, you definitely have a much greater safety factor when using Porta-Boat as your recreational craft over an old fashioned rigid aluminum or fiberglass hull.
2- Advanced Hull Design: Porta-Boat's superior hull design creates a unique stability. Its patented concave cupped bottom LOCKS onto the water's surface. Yet it easily "glides" over logs and limbs and keeps you dry. Even in high winds!
3- Extremely Low Hull Weights: Folding Porta-Boat hulls weigh in at an ultra-light 49 lbs. (21 kg), 59 lbs.(26 kg), and 69 lbs.(31 kg), respectively. Half as much as comparable aluminum boats or fiberglass hulls.
The Deep V Bow cuts into the chop and guides it under the boat. The outer chine forces the spray back down.
Water is trapped in the "tunnel" under the Porta-Boat hull. A conventional vee hull justs rolls over.
Porta-Boat remains "level" in a turn. A conventional Vee Hull "leans sharply" in a turn.
Porta-Boat's Polypropylene hull is almost 1/4 inches thick... twice as thick as an aluminum hull. And, Unlike the thin skin of an inflatable (every inflatable comes with a patch kit!) even the sharpest rocks would have a hard time piercing the almost indestructible Polypropylene material. Many Portaboats are in use off the shores of Florida and the Bahamas where skin divers use them on sharp, coral reefs. They make "bullet proof" vests, rust proof highway signs and automobile bumpers from this "stuff! How puncture resistant can you get?
Almost no maintenance is required. It never needs painting! Why? The color goes thru and thru every molecule. You couldn't rub it off even if you tried. If it gets dirty just wash it off with water. Nothing sticks to it, not even dirt. You won't be spending your time cleaning and "rubbing", just having fun, boating!
PERFORMANCE.... This is where Porta-Boat really excels over ordinary rigid craft and inflatables. Imagine being able to get up on a "plane" using a tiny 3.5hp outboard.
You can when one person is in the boat and at the helm. Porta-Boat takes a standard "short shaft" engine. Do you know what kind of power it takes to get an equivalent sized aluminum or fiberglass boat up on a plane? You would have to invest in a high priced, exceedingly heavy engine that weighs as much as the hull!! And remember, you have to lift this cast iron monster over the transom to get it installed.
The 12' Porta-Boat (3.85m) model was recently tested for stability by the crack Tokyo Fire Department's Water Rescue Scuba Team. They tried everything possible to swamp the craft, including having a diver climb aboard from the bow rather than the stern!
As you can see, he was dressed in full heavy fire department rescue gear! Thanks to Porta-Boat's 5' (1.52m) beam (width) and patented "flexihull", this unique folding boat passed with flying colors!
Please Note.... there was no compensating weight. All the weight was up front when the diver boarded. And, check out the picture on the right. A fully loaded boat with plenty of "freeboard" (space above the water line).
1- Save Time and Energy With an inflatable you have to spend almost an hour inflating and deflating. And, when you're finally through, it really can be frustrating at the water's edge. You've spent lots of time inflating only to find still another puncture that has to be repaired. (You're lucky. You're not out on the water, yet!) Every inflatable comes with a puncture repair kit. It's not coincidental that almost 70% of Porta-Boat sales are made to "former inflatable owners" who have "had it". Below is a picture of what most inflatable owners fear most!
2 - EFFICIENCY! Porta-Boat has an extremely efficient hull design. A "deep keel-twin hydro-tunnel flexihull® design" traps the bow wave and guides it under the boat. This dramatically reduces drag and increases stability significantly. It requires only a fraction of the horsepower of an inflatable craft, which is really more like a floating waterbed than a boat. For example, with one person sitting in the 12' 6" model and with only a 3.5hp outboard (weighing less than 28 pounds), it will actually get up on a plane in less than 5 seconds! You would need at least a 10hp outboard (weighing over 70 pounds) to even come close in an inflatable!
3 - Interior Space! Also, in an inflatable, fully 40% of the interior space is taken up with the air chambers (unless one punctures). You would need at least a 16 foot inflatable to match the interior space of a 12 foot Porta-Boat!