Secret Rowing Weapon #4: How to trim your shell’s hull

The last post focused on determining if you might have a problem with the trim of your shell’s hull. Here are a few solutions to try if you do have a problem.

01-07-13 - trimmed boats.jpg

A hull that is not properly trimmed is neither as effective nor as efficient as it could be. In essence, energy is being wasted.

Here are four solutions that you can use to trim your hull. Generally speaking, if the boat is out-of-trimit is better to have a hull slightly bow-heavy rather than stern-heavy. The key word there is slightly.

Not everyone will agree with this, but a stern-heavy boat is similar to a coach launch at half speed.  It makes a bigger wake as it pushes through the water—and that means the rowers are paying a price.

The following solutions progress from easier to more difficult. All focus on moving weight fore or aft, shifting it around the boat’s center of balance.

Just keep in mind these suggestions when making changes:

  1. Determine you have a problem
  2. Pick a solution
  3. Measure your critical numbers before making any changes
  4. Record those numbers
  5. Make a change in small increments
  6. Remeasure your critical numbers. Record.
  7. Test
  8. Repeat if needed.

Solution #1: Move Rowers

You know your boat is out-of-trim, right? So let’s try switching rower’s seats.

Quite often rowers are grouped together by size, and this can cause an uneven distribution of weight. If this is the case let’s see if any other combination of rowers might work better.

Can you see them in different seats?  If you are port stroked would a starboard stroked boat provide some weight shift?  Would a German rig (bucket rig) help?

Try changes, remeasure your trim, and see what happens to your speed.

Solution #2: Move The Footstretchers

Let’s be a little more specific, and try some subtle shifts of weight.

If you shift your team’s footstretchers to the bow, does it give you a better look in the water?  What does it do to the trim (try the Quick Trim Test). How about if they are moved to the stern?

As you move footstretchers, you have to keep in mind the impact on the catch angle, and that will be the topic of an upcoming secret weapon. But at this point let’s just keep our focus on the trim of the hull.

Stern-heavy? Try moving the feet towards the bow. One notch at a time. Then measure both trim and your speed.

Bow-heavy? One notch at a time to the stern.

See what happens, and test. Again, catch angle will be an issue, but we can fix that once the hull is trimmed.

Solution #3: Got A Wing?

In some boats wing-riggers will have additional holes with which to mount the wing—providing some adjustment for center of balance and trim.  Side-attached riggers usually do not have these holes.

If you are out-of-trim try moving the riggers in the opposite direction of the heavy end of the hull. Bow heavy? Try moving the riggers one notch to the stern, and then test by measuring and rowing.

Like it? Leave it?

Hate it? Readjust and try again.

Solution #4: Add Weight To The Boat.

I have only done this once to try to get the hull trimmed. It was at a World Championship and the coach was experimenting. We needed to add weight to the boat so it would make the minimum standard so we put it all in the bow, as the coach thought the boat was slightly stern-heavy. I cannot remember if he liked the final product but it did seem to make a difference.

However, I would not suggest this as a solution to use, except as a last resort.

So there you have four solutions to a boat that is not trimmed.

Have you tried any? Have other suggestions? Let us know in the comments below, and happy trimming.