Small Boat Design

Discussions around designing small boats including kayaks and canoes.

High Performance speeds versus hulls...

Over the summer, just for kicks, I drew up a large graph with hull speed on the vertical and drag-poundage on the horizontal. Most of you guys are probably familiar with these formulas, one done by Matt Broze that Sea Kayaker Mag always incorporates into there reviews. The results were surprising. I discovewred the following...

My common paddling speed working against aproximately 3.8 pounds of drag has speeds nearly identical for all kayaks over 16 1/2 feet. Narrower hulls, or longer 19 foot hulls didnt offer extra speed for my common effort against 3.8 pounds. To look at the graph itr was interesting to find a lot of the grphed lines seemd to gather or bisect at this point. The sports car kayak seemed to do as good as the common volkswagon.

High Performance hulls really shine when the kayaker is putting in an athletic amount of energy - typicaly over 5 pounds. Here the graph lines began to splay and some real differences were apparent. When that much drag was being paddled against via the paddler, the ferraris step ahead of the volkwagons. "FAST" kayak hulls it became clear, merelly ALLOW the paddler a higher speed.

Shorter kayaks gave embaressingly good efficiency for my 3.8lb. drag factor. Speeds like 4mph seemed to come at a discount with a 14' hull as compared to an 18'. Nothings free tho and what allows the paddler to so readily and easily to hit that speed also keeps you confined to it as this is the outer edge of the hull speed. Sprinting 6 mph wouldnt happen here - not with my back and arms anyway.

It was sobering to see some marquee named FAST kayaks having little or no more speed advantage for my paddling drag/lbs. than a lot of common touring hulls. As nice as ther numbers are for shorter kayaks drag/lbs. factors, I just dont like the idea of the hull speed confinement as something that I can actually touch. I may never paddle my West River 180's hull speed and thats fine. Knowing I have probably more hull speed than i would use is a luxury in its own way.