Re: [Paddlewise] Floatation bags vs dry bags

John MacKechnie asked:
>>>>>>I've read numerous times that folks sometimes rely on dry bags for
flotation
in concert with flotation bags or by themselves on occasion.

Has anyone observed the efficacy of these two forms of flotation in a kayak.

My guess is that the dry bags will not  be as efficient as dedicated float
bags.<<<<<<<<

For a detailed discussion of "Flotation and the pros and cons and
vulnerabilities of different flotation methods read the "Flotation" manual
on our website. Look for it in the "Manuals" pick box.

To answer your question directly: It depends on the volume each system
displaces and the weight of you your kayak and gear to whether you have
enough flotation or not. Several large gear bags that fill up the space that
you aren't taking up yourself would work better (provide more buoyancy) than
some small whitewater kayak sized float bags just stuck in the ends of your
kayak. Size matters! Most float bags I've seen are inadequately small to be
used in sea kayaks. I like the float bag flotation system (and mostly paddle
with them rather than with bulkheads).

As a store owner I would rather buy something ready made by several
different builders (to sell in our store) rather than have to make it
ourselves or have it custom made for us. Supply is so much more reliable
that way. Because nothing big enough in float bags was available we were
forced to have sea kayaks sized float bags custom made. Now that I am
retiring I'd love to see large sized float bags available elsewhere so I
don't have to continue to keep enough available to supply the future needs
of those who have purchased kayaks from us (that use the float bag system
for flotation). Does anybody know of any other source for very large sea
kayak sized float bags?

A float bag should fill up most of the space not taken up by the paddler.
You don't need to leave room for gear in advance because the float bag can
always be deflated as much as necessary to accommodate the gear in water
resistant bags that you want to add. This way the displaced volume is
maintained by the combination of gear and float bags. In general, gear bags
by themselves won't be able to displace as much volume as a big float bag
that can be topped up to fill the space available and the gear in them will
add some weight (and something bulky inside them is necessary to maintain
the volume--because few are air tight). The plus side is that a puncture in
a gear bag with gear in it won't have much effect on your buoyancy but a
float bag will eventually go flat if it is punctured. If you leave the float
bags inflated between paddles you will know if they have a slow leak or not.
If they have long enough inflation tubes that you can inflate them from the
cockpit, one with a slow leak could be inflated while paddling if necessary
before you have a chance to repair it.

Gear bags need to be smaller than float bags as it will be too much struggle
to get a full sized one in place in the kayak. Too many small gear bags have
too much space between them (where the water can flow) so aren't as buoyant
as a larger one. You can maximize the buoyancy by getting gear bags that
just fit inside the kayak when they are full. I like to use a large tapered
gear bag in each end of the kayak and then an extra large rectangular bag to
fill up most of the rest of the space available between the tapered bags and
me. This way the gear bags are small enough to load into the kayak and carry
up to camp easily but not so small to lose too much in buoyancy. Another
problem with a bunch of littler bags is keeping them from floating out of
the kayak like a bunch of ping-pong balls could in a capsize. You always
want at least the bags closest to the cockpit to be big enough to form a
plug that will not be able to float out (or have some other method of
securing the bags in the kayak).

Having the gear bags full of gear does sink the kayak lower in the water and
therefore reduces the positive buoyancy you may need to be able to get back
in the kayak before pumping it out. This is no different with a bulkhead
system though. The key here is having a big enough kayak so the reserve
buoyancy is adequate for someone your weight and the addition of a heavy
load of gear.


Matt Broze
www.marinerkayaks.com
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