Weight of load/paddler vs. boat volume

Some responses to other posts in other threads have brought up a question. Does a lighter paddler weight (and lack of gear load) make a higher volume boat sluggish and slow?

I am 5’11" 190lbs, boat load of food, water and crap of 75 to 85lbs in a WS Tsunami 170. I can easily keep pace with the group of other 14’/ 17’ boats with lighter loads. With no load the boat seems quicker. My wife HATES the Tsunami, she is 5’10" 115lbs, the boat does not swallow her up, but she thinks it is like a bath tub and would rather be in a Pungo.

In another thread a smaller paddler commented on being light weight and not liking a boat and was advised that lighter weight can make a boat seem sluggish.

If a person fits a boat height wise, and the cockpit is padded to fit correctly, does lighter weight in a higher volume boat actually down grade the boats performance by lessening the water line of the boat?

I’ve never known a boat to get faster
when loaded. Some boats certainly feel more stable with a load.

A boat with very proud stems will have a somewhat longer waterline length with a load. As such, the theoretical maximum hull speed might go up slightly. But the wetted surface area also rises and I think for most paddlers this will be a more significant factor in how fast the boat feels.

A lot of boat (and paddler) sticking up out of the water catches a lot of wind. If the wind isn’t at your back it’s going to slow you down. The windier it is the more it’s an issue.

…and, possibly more 'tippy’
By sitting higher in the water with a lighter paddler, the width on the water is narrower, while the paddler sits higher, relative to the water.

Theorectically, it probably does.
"If a person fits a boat height wise, and the cockpit is padded to fit correctly, does lighter weight in a higher "

Theorectically, it probably does.

After all, a boat is designed for optimal performance when in the water a certain depth with certain waterline length. So drastical deviation from that “ideal” would eventually affect the performance.

In practice, that performance degradation is probably relatively minor compare to other factors that are definitely more significant. As mentioned by others: windage, stability etc.

In reality, “a paddler fits a boat height wise” but significantly lighter than designed would be a very tall and skinny paddler… :smiley:

As a smaller paddler…

– Last Updated: Dec-23-12 4:25 PM EST –

Usually, but it isn't just the water line. Each stroke in a too big boat is significantly more and unneeded effort compared to how hard they would be working in a more suited boat.

A kayak (and canoe as well) that is too big for a paddler will be slower because it will not reach its design waterline. Hence the lightweight paddler is not getting the advantage of the hull profile that the designer was planning on.

A boat that is too big will also be hard or downright unpleasant to handle because it will be hard for a too-small paddler to get on edge to turn, maybe impossible. Same for rolling unless it is one of the rare hulls that will behave OK for a huge range of paddlers, like the old NDK Explorer or the newer Nordkapp LV. But a better fit still works best - the Pilgrim by NDK designed to handle smaller paddlers handles more adroitly than the Explorer for its target audience.

Even if the boat is padded out in the cockpit and loaded with shit to hit the waterline, the person trying to handle it will still have to go thru gyrations to handle it rather than just being able to easily and thoughtlessly drop the boat on edge to make it go where they want.

The too-big kayak boat will always be a barge, even in forward motion, hence not much fun to paddle on more aggressive or longer trips. (Though getting someone into a too-big boat is a pretty good way to make them stay home over time.)

But the issues it creates for more adroit maneuvers, especially in a kayak, can be worse. It can make the difference between being able to get a boat turned quickly or not.

As an aside, there are a rather good variety of boats out there now for smaller paddlers, including used. You can do better than a Pungo in terms of features like dual bulkheads etc.

I Can Relate

– Last Updated: Dec-23-12 4:40 PM EST –

I also HATE to paddle more boat than I need. Even on a calm day too much boat is harder to turn and you feel like you're sitting on a bobber. In too much boat you're trying to control the thing. When you're down low and minimal you feel like you're a part of the thing.

I completely agree with Kudzu
four of us were just talking about that a few hours ago while we were paddling. Put a lighter paddler in a large volume boat such as an expedition boat, and it will be higher in the water, and the wind could play havoc.

Jack L

30-60% of volume
I did read somewhere that best performance is achieved for a total weight (in kilograms) of approximately 30% (30% at least, maximum 60%) of the kayak volume in liters. Example: 108 kilos, max 216 kg for a 360 liters kayak, (ex 80kg paddler with 28kg kayak of 360 l).

The article was a speed test of many seakayaks, written in German.

my wife uses Pungo as slang
for all wide rec boats. We still have a 120 Pungo as a new guy beginner boat.

bobber boats
I like big boats. Putting a load on may lower the center of gravity and make a canoe feel more stable, but it puts a lot of boat in the water which makes maneuvering much more difficult. I really like the lightness of big boats with a lot of buoyancy, not to mention all that freeboard.

the Tsunamis
do seem to glide better with some load… they make great campers due to their large volume. I bet your 170 could swallow up a lot more than 75 lbs, I’ve loaded that much in my 140 before.

Has your wife paddled the low-volume Tsunami 135? She’s probably the perfect size for it, that little boat is quick for being under 14’.

Paddling with a heavy load.
I have noticed at times that it seems I average a faster average speed with a heavy load if it is windy with choppy water.

It takes a long time to get up to speed, but once I am there it stays at speed through the waves.

Whops! Sorry
Re my earlier reply (just deleted and am replacing) - I just reread and realized I had confounded your wife with the wife of another person on this site, said other wife is many inches shorter than yours.

she is getting an Alchemy S
for Christmas, she just doesn’t know I want that boat in the fleet as well.

She’ll love it
The Alchemy is like the NDK Romany/Explorer line - it’ll leave a newer paddler feeling safe enough to try new stuff, but will also do any kind of aggressive work for a more advanced paddler.