Why so seasick on catamaran?

Question

I've heard that the motion of a catamaran can cause more seasickness than a monohull. I thought a multihull would be more steady and thus have less movement to cause seasickness. Whats the difference here?

Answer 1

In calm waters, a cat is more stable, but with wave action the "turning moment" is much higher this is because the hull support is often 15 to 25 feat apart, and on two different planes, thus more movement.  The debate rages on, but the higher the waves, above say 3 feet, the less safe is a multi-hull.

Answer 2

I think the difference is in a rolling vs. rough ride.  A child I knew would always get car sick in his family Cadillac, but never in my families International Scout with it's very stiff suspension.

Answer 3

Seasickness is funny.  Sometimes subtle movements will create more nausea than bigger waves.  Personally, the sickest I've ever been was on a small boat on an almost glass calm sea.  

Seasickness is caused by a difference in perception between what you feel in your inner ear and what you see.  When the boat is heaving to and fro like its a hurricane, what you feel and what you see is similar.  When it looks calm, the little inputs to your inner ear become more nauseating.  

By the way, a good temporary 'cure' for seasickness is to close your eyes.  As long as you're not getting conflict between your eyes and inner ear, your nausea will abate.

Answer 4

I thgink there is truth to it, assuming you are talking about a sailing cat.

Fmr  sailor & will puke my face off on anything but a monohull sailboat.

What gets me is the 4 point roll you get in swells on a powerboat & considering the width of a cat It  might just make it worse.

A cat  can  just move in more directions at once.

When sailing or at anchor a monohull has the "righting moment" of the keel to dampen the side to side wallowing .

Under sail there is a rocking motion (fore & aft which alone does not bother me)) & if heeled over it is a fairly constant motion exc in rough conditions.

Sure there are others w/ better science  .for or against the theory.

All I can go by ,is what my guts tell me.

Best regards

Answer 5

seasick is seasick. where the h**l do you get the idea that different boats give you different seasickness???

It all has to do with the inner ear.