So surf skis are not 14’ because of?
K1 kayaks are limited to 5.2 meters because of?
My CD Extreme kayaks are not as fast as my CD Expedition kayak with a rounder bottom. It’s definitely more tippy but the hills are near exactly in weight, Width and length are the same and similar bow and stern. Higher deck and bow on the Expedition but the glide, speed, and acceleration is easily felt.
Yeah, the “no rocker” recommendation is not valid for waves. I have buried the Clearwater’s bow in rapids and had waves whack me in the chest. If you are comparing two boats though, look at your bow wave. The difference on mine is huge.
The OP is a new kayaker; the recommendation also does not apply to Olympic paddlers who go way faster than 5 mph. I also prioritize the capacity to store camping gear, something that most paddlers don’t care about, and I will never buy a boat without a day hatch.
And then folks will say that ultimate speed only works if you can provide enough power and need to go that speed. Otherwise the extra length is just drag and wasted effort.<<<
Longer boats are typically also narrower so the “drag” factor is a red herring in most cases. You might be able to paddle a 17’ kayak much more efficiently than a 14’ kayak as a result. Most times when I put a person in a longer boat they are amazed at how much easier it is to paddle and how much more glide it has. Remember, longer boats generally float higher in the water. Of course a lot of other factors come into play, but don’t buy into the “longer kayaks are slower” nonsense. It just isn’t true in most cases.
If you’re new to kayaking and looking for advice, read Archimedes . . . Read Archimedes! That will take the mystery out of “buoyancy”, “displacement” and “wetted surface”. No need to reinvent the concept:
An object floats if it displaces an equal weight of water. To match the load carrying capacity of a short, fat, shallow draft boat, a narrower boat that weighs the same must be made longer or deeper to carry the same load. LENGTH “enables” the boat to reach higher speeds before it creates the bow wave and trough explained by the “hull speed” concept. The important point from the hull speed chart is how length increases the speed “potential” of the boat, not how fast the boat will go. Only that it becomes exponentially more difficult to power through the building bow wave and trough, as the boat approaches the listed hull speed.
Water will not compress. Therefore, a wider boat MUST push the displaced water further in order to pass through. Then that displaced water returns as the boat passes. Advanced specialty hull designs have found ways to minimize the bow wave and trough that hampers traditional boat hull designs.
Short boats also climb wave peaks and plunge into the trough of the next wave (with the bulk of that wave washing over the short deck and into the cockpit. Long boats are less disrupted by waves because they can better bridge the wave peaks.
If there is more wetted surface in a longer hull, the effect is only minor and at slow speeds; by the time boats reach cruising speed, the advantage favors the longer boat.
The greatest impact on speed potential is boat length, with other influence being hull form and underwater profile, width, and weight (a “typical” 12 ft boat weighs less that a 14 ft boat which weighs less than a 17 ft boat, unless the longer boat is made of a lighter composite. If a 12 ft boat weighs 54 lbs and a 17 ft boat weighs 68 lbs, the 17 ft boat displaces 24 more lbs of water; if the 17 ft boat weighs 40 lbs or 25 lbs, each will displace 14 lbs or 29 lbs less water).
Of the boats mentioned above, a 17 ft by 20 inch wide boat weighing 25 lbs would have less wetted surface than ANY of those other boats, and it would be faster, but here’s the news flash: if you can only sustain speeds of 2.5 mph, in a 12 ft boat, you may be able to go a few tenths of an mph faster in a narrower, longer boat (especially a lighter model), but you will not realize significantly higher sustained speed. On the other hand, If you can sustain 4.8 or 5.1 mph in a 12 ft boat, it’s time to step up to a 14 ft. If you’re looking for greater speed potential, just step up to a lighter, narrow 17 ft boat and you should be able to manage 6.0 mph before long.
Sustaining 6 mph not happening for sea kayak.
By sustained speed, I mean more than just a max peak. Craig_S managed to avg 5.9 mph in a 24 inch wide 175 Tsunami over a 3 miles course. When I was in my early 60s, I could sustain 6.0 mph paddling my 175 over a 1/3 mile distance from a bridge to the entrance to a marina, and even gained on boats in the no wake zones. Maybe it was 5.8 mph or 6.2mph or 1/4 miles rather than 1/3 mile. I believe otherwise and disagree.
You become confused by trying to interprete only part of my posts. Read the entire post, especially the “if” part.
Current ? Wind?
Max sprint speed in the boats you mentioned 17-6" x 25" boat is?
I’ve been through that and you apparently didn’t read any of it. It’s not relevant anyway, because I can no longer match those speeds. That doesn’t mean others can’t.
It’s relevant if you claim average of 6 mph sprint speed is? 4-5-6-7 mph is not linear in power required.
I’ve been through all of that and we dont agree!
I cant figure out how you calculate speed if you don’t trust a GPS.
I said that I don’t trust a gps where?
So you say amount of power required is linear?
You didnt read what I wrote.
Every word. Cross my heart and hope to paddle. 
Oh, how we just love this topic.
LOL! To put an end to the debate: 1) Paddle a shorter kayak 2) Paddle a longer kayak 3) Decide which one is right for you. Bonus points if you use GPS to figure out which one is faster for you. Double extra bonus points if you paddle both kayaks on flat water on calm days without wind or other mitigating factors. Triple extra bonus points if it is the same paddle and same paddler.
I’m not debating, I’m sharing. Take it or leave it.
I can’t figure out how you calculate speed by passing boats in a no wake zone? Just sharing my thoughts.
