I have read somewhere that you can add up the air and water temperature
to determine the degree of hypothermia hazard. What I don't remember is
the range of total temperature that was relatively safe vs. unsafe. I
did some google searching without finding what I was looking for. I did
find some survival time tables as a function of water temperature, and
one reference that said you should wear a wet suit if either the air or
water temperature is under 65 degrees F.

I am mostly a river canoe person, but I do get out on lakes from time to
time.

Yes, I know quite a bit about hypothermia, have read a lot about it,
experienced it, pulled a hypothermic swimmer out of the water (I still
tell that story 30 years later), etc. I wear a farmer john wetsuit when
I think I might swim. I do not paddle in the wintertime.

Anybody have a pointer to an article with rules of thumb?

Richard

Hey Richard,

When I started boating the rule was water+air temp should equal 100
degrees before needing extra protective gear. Some in our club claim 120
respectfully. Another thing I consider with winter boating is adding a class
number to a normal warm weather run. Ex: I consider a Class II a calss III
in winter.
Mike
"Richard Ferguson" wrote in message
...
I have read somewhere that you can add up the air and water temperature
to determine the degree of hypothermia hazard. What I don't remember is
the range of total temperature that was relatively safe vs. unsafe. I
did some google searching without finding what I was looking for. I did
find some survival time tables as a function of water temperature, and
one reference that said you should wear a wet suit if either the air or
water temperature is under 65 degrees F.

I am mostly a river canoe person, but I do get out on lakes from time to
time.

Yes, I know quite a bit about hypothermia, have read a lot about it,
experienced it, pulled a hypothermic swimmer out of the water (I still
tell that story 30 years later), etc. I wear a farmer john wetsuit when
I think I might swim. I do not paddle in the wintertime.

Anybody have a pointer to an article with rules of thumb?

Richard

Grip wrote:
Hey Richard,

When I started boating the rule was water+air temp should equal 100
degrees before needing extra protective gear.

That's one of the most dangerous "rules of thumb" out there, as there
isn't any combination of temps equaling 100 where it's safe to not wear
immersion clothing.

Some in our club claim 120 respectfully.

This level is closer to realistic, but still not enough. Any such rule
is too much of an over-simplification to be useful or safe.

....stuff deleted

My local waters rarely reach up to the mid '50s (Fahrenheit). The
air can be 100 degrees Fahrenheit, yet the water temperature will not
change significantly. And so, I still need to be dressed in a way
that will protect me against hypothermia. The layers of insulation I
might wear over a wetsuit or under a drysuit will change according,
to some degree (no pun intended), to the air temperature, but I
always have to think about the water temperature first and foremost.

- --
Melissa


I tend to agree with Melissa and Brian. You need to dress for the water
temperature, not the air temperature. The rationale, as Melissa points
out, is that in a capsize, you will end up with your body in the water
and the air temperature won't be a factor, whatsoever. An example of
this is when we had a canoe overturn on the Sacramento just out of Red
Bluff. The two boys were hung up near snags on the side of the river. I
paddled in and extracted one on the back of my boat while the other was
hauled out with a rope by one of the other canoes (by the way, a 150LB
boy scout on the back of a sea kayak creates some interesting stability
issues, but he was already shivering and turning blue in the 45F water).

We reached shore, but even though the outside temperature was 95F+, the
area was shaded and did little to let them warm up. As we extracted the
boat and gear, I had the boys climb the bank and sit in the sun on top.
This did wonders for them in a very short time.

On the ocean, however, getting warm would have been much more difficult.
It is likely that an ocean rescue would probably have been quicker
without since there would be no shoreline hazards or current to be
concerned about (though the conditions that caused the capsize would
still exist).

Rick

Using air and/or water temperature to relate to river grades perverts the
river grading system. Dress for the water temperature on rivers. On the west
coast of Canada you can almost always see the snow that the river is coming
from. It isn't hard to figure the water temperature.

--
Sincerely,
Carey Robson -- www.CanoeBC.ca


"Grip" wrote in message
...
Hey Richard,

When I started boating the rule was water+air temp should equal 100
degrees before needing extra protective gear. Some in our club claim 120
respectfully. Another thing I consider with winter boating is adding a
class
number to a normal warm weather run. Ex: I consider a Class II a calss III
in winter.
Mike
"Richard Ferguson" wrote in
message
...
I have read somewhere that you can add up the air and water temperature
to determine the degree of hypothermia hazard. What I don't remember is
the range of total temperature that was relatively safe vs. unsafe. I
did some google searching without finding what I was looking for. I did
find some survival time tables as a function of water temperature, and
one reference that said you should wear a wet suit if either the air or
water temperature is under 65 degrees F.

I am mostly a river canoe person, but I do get out on lakes from time to
time.

Yes, I know quite a bit about hypothermia, have read a lot about it,
experienced it, pulled a hypothermic swimmer out of the water (I still
tell that story 30 years later), etc. I wear a farmer john wetsuit when
I think I might swim. I do not paddle in the wintertime.

Anybody have a pointer to an article with rules of thumb?

Richard

But what if the water temp is 75F and the air is 25F? ;-)

In that case, the biggest hazard is 6-foot visibility due to the fog...

On Fri, 21 Jan 2005 15:06:44 -0800, Melissa
wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi Bob P,

On Fri, 21 Jan 2005 21:16:16 GMT, you wrote:

But what if the water temp is 75F and the air is 25F? ;-)

In that case, the biggest hazard is 6-foot visibility due to the
fog...

Though not necessarily because of that type of extreme temperature
difference between water and air, I do at times find myself in that
type of visibility due to fog. It's much more reassuring in waters I
know very well though, and it definitely has its own particular
charms. A compass and the ability to navigate is always a good
thing.

I love being engulfed in fog (again, especially if it's in a
situation where I feel confident of my navigational capability in the
area), as being sensitive to sounds becomes ever more of an issue.
On my local waters, foggy paddling also provides some nice wildlife
surprises that can "pop up out of nowhere"...like whales, seals, and
the occasional sea lion, harbor porpoise, or even a shark.

Just a couple of years ago I ran into that sort of difference, but in
reverse. The air temp in Maine was in the upper 80s, while the water temp
was still in the low 40s, in June, the water hadn't warmed up, it was a
fairly cold spring up there. I didn't even get my kayak out of the van.
It would have topped 130 on the "add the temps together" scale, however.

Galen Hekhuis NpD, JFR, GWA
Guns don't kill people, religions do

Melissa wrote:


I love being engulfed in fog (again, especially if it's in a
situation where I feel confident of my navigational capability in the
area), as being sensitive to sounds becomes ever more of an issue.
On my local waters, foggy paddling also provides some nice wildlife
surprises that can "pop up out of nowhere"...like whales, seals, and
the occasional sea lion, harbor porpoise, or even a shark.

That reminds me of paddling in complete darkness not too long ago. I
found it to be a frighthening experience, especially since it was in a
long tunnel with a couple of bends and a drop in which sound bounced off
walls and where dozens of other equally "blind" boaters were paddling
somewhere near me, sometimes with much bigger and faster craft (three or
four person canoes) than my 2 metre (6'7") playboat.

--
Wilko van den Bergh wilko(a t)dse(d o t)nl
Eindhoven The Netherlands Europe
---Look at the possibilities, don't worry about the limitations.---
http://wilko.webzone.ru/

Carey Robson wrote:

Using air and/or water temperature to relate to river grades perverts the
river grading system. Dress for the water temperature on rivers. On the west
coast of Canada you can almost always see the snow that the river is coming
from. It isn't hard to figure the water temperature.

Yep, I agree. Paddling glacier melt rivers in the middle of the summer,
one learns that lesson very quickly! If I'm too hot, I'll roll to cool
off, if I'm too cold because I didn't wear enough for the water temp, I
might die.

--
Wilko van den Bergh wilko(a t)dse(d o t)nl
Eindhoven The Netherlands Europe
---Look at the possibilities, don't worry about the limitations.---
http://wilko.webzone.ru/

On Fri, 21 Jan 2005 16:11:29 -0800, Melissa
wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi Wilko,

On Sat, 22 Jan 2005 00:29:36 +0100, you wrote:

That reminds me of paddling in complete darkness not too long ago. I
found it to be a frighthening experience, especially since it was
in a long tunnel with a couple of bends and a drop in which sound
bounced off walls and where dozens of other equally "blind" boaters
were paddling somewhere near me, sometimes with much bigger and
faster craft (three or four person canoes) than my 2 metre (6'7")
playboat.

Obviously, you lived to tell the tale. How are the other paddlers?
:-)

I also enjoy night paddling. Visibility is less of an issue in an
urban setting and/or if not in a long tunnel! I've paddled many times
at night in the Seattle area, and that can be a real pleasure.

Out here, there aren't many light sources other than the moon, so
most of my night paddling here is done under a full moon on clear
nights.

Here's a little something I wrote a couple years ago after waking up
in the middle of the night and going for a full moon paddle:

============================
Sings My Heart

dark purple sea
dreams in the light
of magic and moon
watersprite, awake!
it's time to dance

give me your hand
i'll take you where
gravity floats
and light sings her song
of uncharted depth

sings my heart
this silent song
sings my spirit
these waves of joy
give me your wonder
it's time to float

i recognize this
my waterborne life
this undeserved gift
this dance of tides

bring me ever home
my sea of moonlit dreaming
==============================

I used to explore caves. One of the most terrifying things I can imagine
would be to be kayaking in a cave down a rushing underground river when the
passage and river keep on going but the airspace doesn't. This, of course,
takes place in the dark, cold underground, your light having gone out long
ago. Paddling upstream I could handle, downstream is something I'd rather
avoid. In a non-overhead environment I could see how it could be quite
attractive, however.

Galen Hekhuis NpD, JFR, GWA
Guns don't kill people, religions do