PaddleWise Discussion on Boat Trim
Date: Mon, 11 Jan 1999 20:04:19 -0500
From: "Robert Woodard"
Subject: [Paddlewise] Trim
Folks, I'm new to this list and a *very new* paddler. I recently finished a
"stripper" kayak and the first few times out on the water with it have been
a nightmare to control. I'm sure 100% of the problem is my inexperience.
I just finished reading the articles on the Paddlewise web site about
ballast. I know you folks discussed this in depth back in February of last
year in quite a bit of detail. I don't wish to rehash this, but would like
to ask a few questions. A few quotes from the web articles and a little more
description about the control problems I'm having first:
"A bow heavy boat will tend to start out okay and then suddenly turn."
This is exactly the problem I had the first time out, I had a 15-20lb
backpack on the front deck and the kayak (nothing in the forward or rear
hatches) and the kayak was almost impossible for me to control.
" A stern heavy boat will tend to wander and require more corrective
strokes."
This is more how the boat behaved my second time out. This time I had placed
most of my "stuff" in a dry bag in the rear hatch. Only safety equipment
(spare paddle, paddle float, bilge pump, etc) above deck and nothing in the
front hatch. It still felt a little like the first time out though.
"Like everything, the more extreme the weight differential the worse the
effect. I would expect less dramatic handling effects in a boat with more
rocker."
This kayak has a moderate rocker, weighs about 45lbs, 17 ft long. I weigh
about 170, 5'9". my paddling skills are at a very beginner level. The boat
also feels very stable to me. I don't have a problem at all with stability,
my concern is with directional control.
"Also ballast cures other problems, like excessive weathercocking"
I have this problem (weathercocking). It tracks well into the wind, but
wants to turn hard in following waves.
Re: seat placement:
"Yes, an inch will make a substantial difference on boat trim and handling
characteristics. I would suggest moving it in smaller increments, say 1/2"
or less at a time & then paddle to evaluate the effect. "
Question: Is there a way I can tell if the boat is "trim" before I get in
and close the spray skirt? It would seem that trim would be a moving target
based on what I was carrying for the day (winter/summer gear, day trip,
camping, 2 hour "stroll", etc). Getting in and paddling for a few minutes
every time I take it out and then land and make a trim adjustment doesn't
seem very practical.
Question: Is trim related to center of balance? This kayak (with no gear)
has a center of balance near the very front section of the cockpit. If so,
can I play around with trim until I'm happy with the way it tracks, get out
and mark/note the center of balance, and just pack it in the future for
center of balance in the same place?
I was thinking of adding a more pronounced keel on the rear half of the
kayak to act much like a skeg. After reading the articles on ballast, I'm
now thinking I should hold off until I improve my paddling skills and make
sure my problem isn't because of trim.
Last question: Is trim just "fine tuning" or can it have dramatic effects on
control? While willing to admit I have a lot to learn, I want to believe
that my paddling is not THAT bad.
Again, this isn't a stability issue, but one of control. Your thoughts on
what I should try on my next outing to narrow down the cause are much
appreciated.
Thanks in advance,
Woody
Date: Tue, 12 Jan 1999 07:54:16 -0500
From: "John Winters"
Subject: Re: [Paddlewise] Trim
Experience will tell you when the boat is properly trimmed. As you have
guessed, it will vary each time you paddle so for boats that are sensitive
to trim a sliding seat can be a godsend.
The kayak's center of balance has very little impact on how the boat trims
relative to your impact. You weigh more than three times the weight of the
boat and a small shift of your weight has a major impact on trim. If you
carry a lot of gear you can use it to trim the boat. I do this by "by eye"
and over the years it seems to have worked out just fine.
Paddling skills are important and holding off until you feel confident the
problem can't be solved that way makes a lot of sense. On the other hand,
if the boat can't be controlled without a lot of frustration, a skeg or
rudder can help you get past the frustrating part as you learn. Every
paddler learns in his own way and at his own pace.
Some boats have greater sensitivity to trim than others. Personally I
prefer to fit the boat to the person rather than fit the person to the
boat. You will determine how you want to approach the problem. The ebst way
for you may not be the best way for some one else.
You may want to ask people with the same kind of boat about their
experiences. That may give you some insight into what you should expect
from the boat and maybe some one will have found a good cure for the
problem.