what is the best material for rigid inflatable boats?

its a pretty tough question and to some extent subjective, pvc glued seams are in many cases short lived hypalon glues seams are very long lasting and polyurethane also short lived . Glued Hypalon seams are more of a mechanical bond, the fabric is prepared with abrasive paper, primed and glued, when it comes to P.V.C however you use a solvent not just to clean the surface but to open the pores of the material enabling the adhesive to grab something. PVC is not typically sanded/abraded when preparing so saves a substantial amount of time also it can be heat, friction and ultrasonic welded, while this is a massive advantage it is also its disadvantage since like many things that are heated to melting point it becomes more brittle less able to stretch and contract, when you weld steel and metals you are adding material to join the surfaces and penetrate the surface together, With P.V.C and p.u the existing surface material is fused and thins out. PVC has no uv barrier which is why on sunny days if you get under your boat the tube is glowing, U.V deteriorates adhesives even hypalon glue wouldn't last if Hypalon didn't have a form of blackout layer. What a few companies have tried to combat U.V is to paint the inside of the tube with a type of paint or sunblock but not sure how much it has helped.

Toughness?

Hypalon (csm/ca) is softer than both P.U and p.v.c so it is less abrasive/wear resistant. P.U is the toughest in that contest

Manufacturing?

Hypalon takes longer to manufacture from because of its requirements to be thoroughly sanded, cleaned,primed this used a lot of materials and solvents adhesives that all cost a fortune. so both p.u and pvc take advantage since they can both be welded saving manufacturing time and money in adhesives they prove to be a manufacturers dream in production no waiting for glue to set, no preparing, less staff.

Repairing the product?

When it comes to repairing hypalon has its advantages it is mechanically sanded glued and contact bonded. P.U and P.V.C require some skills. They can be welded or glued but adhesive is harder to get to bond the older the material you are attempting to stick to. So in some cases they may require some form of keying up/preparing of the materials, and even then they are still more difficult to get to successfully bond Also because the adhesive has been exposed to uv for many years when you are attempting to fix a problem the old adhesive will be weakened all over, a repair the size of a finger can soon increase to the size of an arm length or in some cases require a full refit before it could be considered a safe repair by professionals which is why companies often say its retube time. Because they don't want to be held liable should something go wrong. So Hypalon wins this category

Longevity

Hypalon, PVC and P.U have made some good changes over the years and the products are lasting longer than before not quite in the same league as original avon fabric but then nothing has, p.u and pvc in the past have been pretty terrible fading and discolouring in a matter of a few hundred days often by the time they have reached 10 years old they are showing canvas however this fortunately has got better and with care from the owners they have been known to last close to 20 years. Hypalon while also being the more uv resistant has suffered in some ways since some colours didn't fare well in uv but overall hypalon was the clear winner in longevity with owners taking care the material is lasting over well 20 years.

Price

P.V.C is cheapest although there are versions/ brands such as mehler, Valmex, Hitex, Duratex that are not so cheap the best

P.U is in the middle but not that far off the super expensive Orca Hypalon.

Looks?

Looks most of these materials to the untrained eye look and feel very much the same, you will likely feel pvc and P.U being harder surface and hypalon being more rubbery. hypalon comes in several different impressions like carbon perlage honeycombs or hex or the standard matte looking fabric impression. P.V.C has a far wider range since it has several textures like dimond,carbon,hex dimple,and mash up colours like camouflage patterns.

P.U seems to just have basic smooth in a variety of colours.

Which material is best?

So which is best is down to preference and use if you want a work style boat that can rub up and down a cheese grater ide almost certainly recommend P.U it's tough and durable and extremely wear resistant. finding people to repair P.U is certainly going to prove challenging however, in the uk there is probably 1 company that claim to carry out repairs based in Hull so if you are southern or Scotland it would be a hard pill to swallow.

If you want cheap boat that does the job and are going to flog it off after a few years pvc is probably the way to go just bare in mind that it might not last longer thn you own it and may have to spend a lot to get it repaired since more and more companies refuse to work with P.V.C.

If you are looking for something that will last close to or more than 20 years, be pretty good looking with the selection of colours, that will hold up to UV, be readily repairable at almost any repair shop and money wasn't a crippling factor ide highly recommend Hypalon.

If you are a manufacturer looking to saving money manufacturing and selling many boats at a cheaper price that may not as long but with a cheaper price tag are more likely to sell, save production, less staff cost, save time welding seams, and maybe get more after sales income in repairs ide certainly recommend P.V.C and P.U.