Tsunami 140 rough bottom?

@E.T. said:
Is is normal for the new Tsunamis to have rough bottom? The rest of the boat is smooth, but the bottom and lower edges (most parts that are underwater) are rough like sandpaper? I would think this would slow me down? My older tsunami 125 is not like this.

I think it would depend on what grade of sandpaper it feels like. We used to sand the gloss off the hulls of racing catamarans with 400 (vs. wax) I’m not sure at slower speeds it would help that much but would make the kayak easier to handle out of the water and every little flaw or scratch wouldn’t show up in the store.

@rival51 said:
@Overstreet I somewhat recall that Greg Barton experimented with a texture or micro grooves in his racing days.

Found it in the FAQ on the Epic site: https://www.epickayaks.com/faq Go to the “Should I Wax my Kayak” section.

A good fact-based discussion of the issue, thanks for pointing it out.

@Sparky961 said:
This all may be true, but I’d put money on it being primarily to reduce the cost of the mold. It’s much less expensive to produce and maintain rough surfaces than glossy smooth. Hand this factoid to the marketing people and watch them spin…

“It’s a feature, not a bug”.

Interesting. After reading the other replies, it does sound like this rough finish is mostly marketing BS. While the roughness may not be helping, hopefully it isn’t hurting me, either. I wonder if it would be worthwhile to try to smooth it out with a buffer or something, or just leave it be?

My buddy has a 17’ Tempest, and I asked him about it the other day. His entire boat is smooth. It’s also fast as hell, but I think that’s mostly due to him…dude is a beast.

My buddy has a 17’ Tempest, and I asked him about it the other day. His entire boat is smooth. It’s also fast as hell, but I think that’s mostly due to him…dude is a beast.

And it’s a Tempest 170…

I’d try to knock it down with a fine sanding block or wet sand it with fine grit. Realize, you will put dings and scratches in it through normal use.

I would leave it alone.
Sanding PE it might very well make it much worse

@grayhawk said:
I would leave it alone.
Sanding PE it might very well make it much worse

Agreed. You’re going to end up with a very fuzzy mess. Anyone should consult a physics? major if they want to know which is better in terms of hydrodynamics. But really, for a 14’ plastic boat, this is the least of the problems.

@E.T. said:
My buddy has a 17’ Tempest, and I asked him about it the other day. His entire boat is smooth. It’s also fast as hell, but I think that’s mostly due to him…dude is a beast.

You aren’t comparing the same fruit. 17’ vs. 14’, the longer boat will win when it comes to flat out speed in most plausible situations. But also as you suggest, the paddler can have a huge effect on this. I frequently paddle with a person with less height and muscle mass. I often take my 14.5’ boat instead of my 18’ (17’ waterline) sea kayak to purposely give myself a handicap. If I take the long boat I can barely paddle without leaving the other person behind. But with the short boat I feel like I’ve worked a little and can still chat with the other person who isn’t that far away.

If you want a Ferrari, get a Ferrari. Don’t think that putting slicks, a spoiler, and a noisy muffler on your Dodge Neon is going to make it go any quicker.

Note: I’m not picking on the Neon, nor am I saying the comparison between boats and cars is accurate. It’s merely the first car that popped into my head that too many people have spent way too much time and money trying to improve. I also know just about nothing about Ferraris.

The Tsunami is also a higher volume boat than the Tempest, in addition to the Tempest being longer. Higher volume and deck height will likely slow it down.

The basics:

Water line length will determine potential top speed.
Wetted surface area will determine efficiency…

The narrower it is the less wetted surface area it will have and be easier to paddle to it’s top speed.

@grayhawk said:
The basics:

Water line length will determine potential top speed.
Wetted surface area will determine efficiency…

The narrower it is the less wetted surface area it will have and be easier to paddle to it’s top speed.

Agreed, with one caveat: wetted surface area determines the amount of frictional resistance on the hull. It may be convenient to describe a hull with low frictional resistance as efficient, although efficiency is a measure of power expenditure required relative to useful power produced. I’m not sure the term lends itself to paddle propulsion, since the power expended by a person is notoriously difficult to measure, and the useful power produced is hard to define.

OK thanks…
Would it be more correct to say?

“Water line length will determine potential top speed.
Wetted surface area will determine efficiency effort…”

I’m reminded of a sign in an old boss’ office.
“There comes a time in every project when you fire the engineer and get on with it.”

Thanks, all. I guess I will just leave well enough alone. The boat seems to perform fine. I was coming from a Tsunami 125, so this 140 is a bit of improvement. I’m not usually in a huge hurry, anyway. If I’m paddling at a decent clip, I’m usually a little over 4 mph (at least according to my phone app). Today, I actually hit nearly 9 mph top speed, but that was with a good tailwind and I was riding on top of a few, good 3-4 ft waves. Fun stuff =)

The textured surface is intentional.
I had a Perception Pescador 10’ that also had a textured hull, but the 12’ did not!

@grayhawk said:
OK thanks…
Would it be more correct to say?

“Water line length will determine potential top speed.
Wetted surface area will determine efficiency effort…”

Sounds good to me, but based on recent posts, it sounds like my input may no longer be needed…

@carldelo said:

@grayhawk said:
OK thanks…
Would it be more correct to say?

“Water line length will determine potential top speed.
Wetted surface area will determine efficiency effort…”

Sounds good to me, but based on recent posts, it sounds like my input may no longer be needed…

Your input is always greatly appreciated…

@grayhawk said:

@carldelo said:

@grayhawk said:
OK thanks…
Would it be more correct to say?

“Water line length will determine potential top speed.
Wetted surface area will determine efficiency effort…”

Sounds good to me, but based on recent posts, it sounds like my input may no longer be needed…

Your input is always greatly appreciated…

Thanks, I appreciate that as well.