Regarding shooting video at sea and what cameras to use, I will offer
two suggestions based on thirty-five years and counting of being a
commercial film and video cameraman, editor, director, and producer.
First, whatever camera you get make sure it has image stabilization,
preferably optical image stabilization as opposed to digital
stabilization.  Canon has the best system (many other manufacturers who
offer image stabilization actually license and use Canon's system).
Optical stabilization, while the more expensive of the two systems, does
a better job with less impact on the picture quality.  

Second, do not spend one penny on any camera that offers "digital zoom."
Digital zoom is nothing more than magnifying the image on the chip.  So
the more you zoom in the less resolution you get.  Fortunately, this
feature tends to be put only on low-end cameras.

What you want is a camera with optical zoom.  This magnifies the image
optically by moving the elements inside the lens.  Assuming the lens is
well-designed and constructed to begin with there is no resolution loss
when zooming with an optical zoom.

The one "drawback" to an optical zoom is that because it's changing the
relationship of the elements inside the lens as it zooms, it changes the
light transmission characteristics of the lens at the same time.  So
you'll find--- particularly on the less-expensive optical zoom lenses or
zoom lenses with a very long throw--- that the lens will transmit less
light when zoomed in than when zoomed out.  So under low light
conditions or if you're using a high "shutter speed," you may need to
increase your ISO setting or open the aperture when shooting at the
tight end of the lens to maintain proper exposure.

Professional and some pro-sumer video cameras offer gain adjustment.
This brightens the picture when shooting under lower light conditions.
It can be a useful tool BUT adding gain also adds noise to the picture.
We use gain only when it's the only way to get a reasonably exposed
image in low light.  But normally if we don't have enough light for a
good exposure without adding gain we light the subject.  In my case
today this may involve a lot of big lights when we light a 777 emerging
from a paint hangar at night.  I realize lighting something at sea is
not real practical for most non-professional videographers (and it ain't
easy for the pros--- I've had to do it once or twice).  But be careful
when adding gain if your camera allows it, and make sure you don't do
what even professionals do occasionally and forget to turn the gain off
when you don't need it anymore...:-)



_________________________________________
C. Marin Faure
Producer/Director, Boeing Video Services
telephone (206)650-5622
fax: (425)965-4253 -mail: marin.faure@boeing.com