What is the most durable construction currently in use?

'Durability' measured by:

• Resistance to punctures from impacts on small area (e.g. hitting sharp rocks).
• Able to cope with big slams when going over waves.

Most constructions, by most manufacturers, produce a reasonably light craft. So for non-racing use, it seems to me to pick durable over weight-weenie.

Many of the super-lightweight boats use a composite with a core that is vulnerable to crush damage and complex to repair if punctured.

Coping with big slams requires a different sort of durability, and I suspect is influenced more by the quality of the seams (if they exist) than the strength of the hull itself.

It's a tricky balance between lightweight and "tough". My Epic red nose v10 weighs 25 lbs, but it seems very susceptible to impact damage. I've never bumped, dragged, or crashed into anything, but there are several impact impressions along the seam from the previous owner. 

My 2008 Necky Chatham 17 sea kayak in full clear coat carbon construction is practically bulletproof when it comes to crashing over waves and bumping into stuff. It doesn't have a Nomex or foam core. That being said it survived a drop off  the roof of my 4Runner with a US quarter sized chip that cost several hundred dollars to repair. Carbon is strong, but brittle. I'd like to try one of the pre-preg carbon layups from Kai Waa. I've heard the monocoque construction is pretty tough and is very light. 

No such thing as light and tough in the way you are wanting.

Light and stiff is quite another thing and is what paddlers want, and that starts to get expensive. Very fragile for impacts with solid objects and being hammered by a breaking wave. 

As for monocoque construction, that has no relevance to toughness, it still boils down to weight, the lighter they get the more fragile they get for impacts. You have to understand a competitive racing ski has less than 1mm thick outer layer of material, even Steel will have a problem with that thickness for impact resistance, look at a car how fragile they are if you bump into it with a sharp object.

I agree about weight (although I have an old kevlar K1 - bendy bendy but very tough. Copes with impacts just fine.).

It seems to me (just going by specs and vids) that getting weight down from 15kg to under 11kg sacrifices a lot of resilience. For most of us, we'd be better served by watching the calorie intake and dropping 5-10kg of bodyweight.

I believe a single layer hull is typically more impact resistant than a foam core or nomex honeycomb core sandwich. As ranga says, with a sandwich you can get away with very thin skin layers that are stiffened by the core. But the core is a weak point as the thin outer layer is not well supported by the core in a pinpoint area, like you are likely to experience during a collision with something.

Also Carbon has basically zero flex or elongation before fracture, so although it is extremely light and stiff, these properties are negatives when encountering something unexpected.

I think Stellar's Multisport is a single layer construction (that is, multiple cloth layers with no foam core) and its a blend of carbon and kevlar, which has more give before  catastrophic fracture.

As comparison, Kruger canoes makes ocean-faring expedition canoes and they are a single skin layup made of 13 layers of kevlar. A solo canoe is ~60lb and a tandem is ~90lb, so not light weight at all, but when you're crossing the gulf of mexico and a storm kicks up, you dont really want your boat folding in half

In my experience the best lay up is carbon kevlar. You get the rigidity of carbon and the puncture resistance of kevlar. My Huki's with this construction have held really well over the years. Carbon boats are too fragile and fiberglass boats are too soft and prone to dings.

My understanding is that Kevlar is stronger in compression while fiberglass, especially 6 oz heavy duty as glass is stronger in flexion. So most whitewater composite boats are a Kevlar inner and S-glass outer with a hand layup like the Kruger boats. Not sure how carbon factors into this. It is stiffer than either, but that could be a negative in impact resistance.

My Nelo WWR layup is a single skin boat, so it I see a little stiffer than Stellar's multisport so will give some and no foam or honeycomb core to puncture.  No damage except cosmetic so far, though I haven't abused the boat either. Interested in hearing about Nordic's version.

Basically impact resistance and stiffness are on opposite sides of the continuum. All things, like materials and resin being equal the heavier boat will resist impacts better.

--- Andrew