Joey’s got an interesting article on ‘Weight and Durability’ on his blog site.
(disclaimer - my latest purchase greatly resembles the kayaks he is showing)
My main reason for lightweight (quality) kayaks is because I’m protecting a back (that went out on me several years ago).
Carrying a 30# Vs 55# boat a 1/4 mile for my daily paddle makes a great difference.
(not to mention an easy on/off the cartop for the weekend paddle)
I’ve always just taken for granted that once in the water, the weight of the kayak doesn’t matter much, other than quick acceleration (for racers).
However, after reading Joey’s article, it does make sense that weight of the kayak makes a difference in dynamic water - in being able to maneuver it rather quickly.
I don’t have a ‘heavy’ kayak anymore, so I can’t directly compare them, but, sometime I would like to ‘weigh one against the other’ (so to speak) in the surf sometime.
I can see where light weight may help maneuverability. But having owned a 44 pound Swift Osprey and now a 32 pounder I don’t see much/any difference in boat character. I could argue that a heavier boat actually adds some predictability to freestyle maneuvers in a canoe although as you say for racing or ultimate responsiveness lighter will always be better.
Regarding the main point of the article, weight and durability, no offense but I don’t see much substance in the article. There’s a point that newer pre-impregnated fabrics are better if harder to work with. OK fine. There’s another point that many boats lack 45 degree fabric orientation and that “adds exponentially to durability”. That’s quite a claim to make with no rationale or evidence. I think it’s possible that 45 degree orientation might have benefits for torsional stiffness at the expense of bending stiffness. I’d like to see data on the magnitude of this effect and even if it’s real then I’d like to see evidence that it impacts real world durability. I do think there could be benefits (or maybe trade offs worth discussing) but I don’t like unsubstantiated claims.
It is true that the more directions of weave in the fabric, the stronger it is overall, but the weaker it is in any specific direction.
It makes perfect sense, unidirectional carbon (like used in paddle shafts) is extremely strong in 1 direction (which is what you need for a paddle since all the force is predictably coming from a known point), but is very weak in all other directions.
Likewise, a fabric with 0,90,-45,+45 is the strongest weave when impacted at random orientations to the weave, but is the weakest in any single direction because less fiber in the weave is running parallel to the force. Kind of a strange concept but makes sense when you think about it.
You have to compromise strength in any 1 direction for strength in all other directions or vise versa, thus why they make many different weaves, for different force vectors, either known or unknown
Also, weight does play a noticeable difference. Going from a 35lb ski to a 22lb ski is highly noticeable. My experience says you need to change boat weight by around 30% or more to obviously feel it, but subtle differences are noticeable at a smaller delta. Heavier boats are more stable than their identical UL counterpart because there is more mass to roll. This is particularly noticeable on elite boats that have very little stability to begin with.