Fast sea kayak dimensions?

What exactly are FSK parameters? After looking at the Sound Rowers guide, I can honestly say I’m more confused. I had always assumed 18 ft length by 20 as maximums.

Dunno where I got that from, but now I’m starting to wonder if that’s right.

Unclear what you mean
Are you asking about a particular boat or manufacturer’s line. Or are you trying to lump all sea kayaks together somehow, or just isolate racing sea kayaks versus surf and play versus expedition… really cannot tell what you are looking for.

It’s race jargon for a class of boats.

– Last Updated: Jan-25-15 11:59 PM EST –

FSK = "fast sea kayak". I'm no racer or kayaker, but this came up on another thread last week. In racing, every class of boats is defined a particular way, and that's what the OP is looking for, the official definition of the FSK class.

OK - thanks
I hadn’t heard that categorization. It sounds like a production sea kayak that someone would consider likely to do well in a race.

Looks like no dimensional requirements

– Last Updated: Jan-26-15 12:25 AM EST –

Let me edit that title to say "Looks like no *length* requirements."

Looks like what matters is the ratio of the waterline length to the width. As long as the ratio is within specs, you are good to go. Naturally this won't leave much room for length variation, because there's a limit to how narrow a kayak can be, and because extra wide kayaks won't be long enough to have the proper ratio.

The definition on the site should make a lot more sense when you express both the waterline length and the width in the same units (don't mix and match feet and inches, for example).

The range of ratios is 9.25:1 to 10.99:1. You assumed a length of 18 feet so we'll apply those ratios to a boat of that length (but remember to use waterline length when you do this "for real"). 18 feet = 216 inches. Thus, for that length, the width can be anywhere between 19.7 and 23.3 inches. This range in acceptable widths will be different for every different length that you consider. Just do the math as needed.

For racing, you'd want your boat to be as long as possible, but length isn't unlimited because at some point the boat would become too wide to be manageable if kept within the ratio limits they specify.

Sometimes depends on the race
Often it depends on a particular race and its organizers/riles. The same boat may be in a different class in different races. Often, the more important factor (or at least one of them) is the Length to Width ratio. So, an exceedingly skinny boat of short length may end-up competing with longer but wider boats. Often the measurements are taken at the 4" (or actual) waterline, not the overall dimensions of the kayak.


Rather than getting into race classifications, especially if you’re not racing, what info are you looking for? A fast sea kayak?

See you on the water,


The River Connection, Inc.

Hyde Park, NY


I remember how confused I was when I was about to buy my 1st kayak …so I adopted this rule …short and fat is slow and long and skinny is fast.

So, you find the effective waterline (minus rocker) and divide the waterline from the width?

Is that right?

And no, I’m not necessarily looking for a boat, just trying to understand how race class determinations are made.

yes its waterline length/waterline width
here’s the list of boats from our group

If you are looking for a boat for racing I would see what the local race population is using. You’d be very lonely in the FSK cat in our Sound Rowers races, but on the plus side you’d usually be guaranteed a ribbon.