JohnHuth

I'm glad I'm not the only one who has problems putting a spray skirt on underwater - I thought this was a unique clumsiness on my part.

On Sunday, I met with two fishermen who regularly ply the waters in and around Nantucket Sound. One guy introduced me to the other as "this is the crazy guy I was telling you about who wants to kayak in the Muskeget Channel".

They proceeded to regale me with tales of sorrow and woe associated with the channel.

"I had a friend who was fishing off of Nantucket, when a 20 knot wind picked up from the southwest. He was going through the channel and saw 10-15 foot waves all over the place. It was real hairy."

and on and on with about 5 or 6 of these stories. I came away with a sense that it's a tad funky when the wind is up and the current's running. Just a thought.

He also confirmed that there's a significant flow of water just west of Muskeget Island, and that there is a small channel there.

I'm quite comfortable in the 170, and I'm not that large. Maybe I'm doing something wrong? The leg placement makes me feel like I have a lot of leverage - as I can bring force for pitch/yaw/roll efficiently.

Temperatures are a bit warmer now than these averages. Example: Boston Harbor is around 41 degrees F - not out of drysuit territory by any stretch of the imagination, mind you.

I have a fiberglass Tempest 170 - it's great!

My only minor nudge is that the hatch covers tend to leak - there are various purported cures for this. This only really shows up in heavy seas, with lots of wash over the deck. It's never been so serious that I've had to resort to RTV to cure it, so it's manageable.

Overall - great tracking, good at carving turns, surfs well, easy to roll. I'm 5'10" - am XXX pounds, but look much lighter.

John Huth

Hmm....

I wonder what Adam Bolonsky would use for a lure for this one? A half-size gray seal imitator? It might be interesting to land.

I tried to poke around for any statistics I could find. I'm guessing that the situation of "stay with a large boat" versus "paddle to shore" hasn't had any documented successes or failures, so it's a bit speculative. I'd head for shore, not knowing anything about the vessel I was next to, despite the USCG advice. I found a few freak examples - people in Outward Bound on Hurricane Island who got zapped on the beach from a bolt that struck a nearby tree and the current traveled through the roots.

The main problem with thunderstorms is wind. When I see a squall front bearing down on me, my first thought was to worry about the wind, and I didn't give a thought to lightning.

The question is primarily academic, given the lack of data, but having seen some freaky lightning, I'd stay away from the boat with the tall mast.

My scariest experiences were in the woods - with neighboring trees that got hit repeatedly. The other data point is on Electric Pass - up in the Rockies. It is total folly to be on this pass in the afternoon in the summer. Your hair stands on end, and you hear a buzzing sound. Many people climbing over this pass experience this - very dangerous!

I'm starting to run out of practical experience, here - I can only speak to the physics and now enter the realm of my opinion. There are probably statistics compiled about this kind of thing.

My concerns with an aluminum mast with a groundstrap to an electrode in the hull would be two-fold: First: transient (very fast) currents can take erratic paths, and might jump from the mast, directly to something else, depending on the "inductance" (tendency to resist fast current changes) of the path through the hull, Second: I'd worry about the reliability of the connection - the electrodes are subjected to a lot of oxidation and could lose conntection to the mast over time. On the other hand, a pointy, lightning rod structure might provide a continuous discharge and relieve the charge build up before it became an issue of a strike.

Even armed with the knowlege that most boats with aluminum masts have a ground strap, I wouldn't seek them out in a thunderstorm as safe against lightning. In part this is my own internal risk-evaluation. The odds of something going wrong is small, but the consequences are huge.

It's certainly true that, given some time, you could design a system like this. If I had to, from scratch, I'd probably use a mast with a lightening rod, and perhaps some barbs on it, and then have a good groundstrap (like what welders use) and then run it to some electrodes on the bottom of the hull. That would probably cause a sufficient charge dissapation from the sea and boat to the atmosphere to reduce the chances of a strike substantially.

This is, in principle, what happens with St. Elmo's fire.

The problem, as I see it, is that any random large boat will be a larger target for a lightning bolt unless it has something to dissapate the charge, like a system like this. So, if you knew a vessel had a system like this, it would likely be safer, but if you had no idea, the vessel, in all likelihood wouldn't, and then you'd be more likely to get hit from an arc skipping off the mast.

Some more thoughts:

Lightning occurs because the clouds acquire a large positive charge on top, and negative charge on the bottom. The convection/condensation of large updrafts feeds this.

On the ground, positive charges are attracted to the negative charges on the cloud bottom. The charges tend to congregate most on "pointy" structures.

The potential difference between the ground and a cloud can get past 1 million volts, and depending on the geography and other factors, the charge concentration can get to be high enough to make electric fields that will ionize air.

Once you get into this situation, the chances of a breakdown, making a charge channel out of ionized air is very high, and pretty unstable. For someone making apparatus that runs at high voltages, this can be particularly annoying, as it's difficult to eliminate little points that will periodically arc over.

The lightning rod will work for continual discharge. St. Elmo's fire is a variation where the pointiness of the masts of sailing vessels would make a continual discharge into the air, neutralizing the charge. Here, a low current that feeds from the ocean into the masts and into the air provides a slow release of charge.

In other cases, the charge may build up until the field gets very high, and then, suddenly, the charge channel will open up, and a very high current bolt of lightning will occur. In this latter case, the actual conduction channels are much more dicey. They can arc over all sorts of structures, and take funny paths.

In the case of a sailing vessel or boat with outriggers, I wouldn't count on a lightning rod effect, although I suppose you could outfit them with lightning rods. The ends of the masts are usually rounded and have some kind of pulley on them for the sails, so I don't think these would act like lightning rods, and would tend to be more of the variety that would build up charge and then have a large bolt, in which case, there are no guarantees about the conduction path to the water.

In the case of a shallow cave, you're getting an arc down the face of a cliff, and it frequently arcs over the faces of shallow caves.

I hope this helps.

As luck would have it, there's an internet connection here. But, the surf's calling and I can't go through all of this. A few physics points:

1.) The lightning rod is a design by Ben Franklin. "pointy" structures tend to have large charge concentrations and large electric fields. When the field gets high enough, the air begins to become ionized - this immediately opens up a conduction path - much like a wire. Tall trees and structures often are hit because they offer up the largest, isolated, collection of charge and hence are the first place to see breakdowns of the air when there's a large buildup of charge.

Franklin invented the lightning rod as a very pointy metallic object to put on the top of steeples, etc. The idea is that the "pointiness" is so sharp that there is huge electric field, making a nearly a continual discharge, and it doesn't allow the charge build-up in a normal steeple. Without it, one would tend to get a very large charge build-up, then an instability, then a bolt. The lightning rod provides, in a sense, a continual electrical discharge - a lot of very tiny lightning bolts, rather than one massive one.

2.) Unless a boat is equipped with a real lightning rod, it's subject to the possibility of a large charge build-up. If you're near a boat that gets a discharge, it's anyone's quess what the path would be, but I think it would scare the daylights out of me, even if I wasn't in a conduction path. I'd stay away.

3.) Shallow caves or shallow overhangs: avoid them - frequently the path to ground will arc over the top of a cave and will find a conduction path through the cave or overhang.

4.) Someone pointed out the random nature of strikes - this is true, up to a point. There are structures that tend to collect charge, and it's not always easy to see the conduction paths - depending on how much seawater might be sloshing onto a buoy, or how wet a surface one might have.

More when I get back

I'm open to any suggestions.

Part of my problem is that I have a high metabolism rate. I have a Goretex Kokatat (sp?) and the gaskets aren't so bad - maybe it's the layer of polartek underneath I put on. I try the immersion test, and I find that a layer of polartek works well, but if I paddle on a hot day in April, I sweat a lot. I don't know of a way to ensure you'll stay warm in the water in April, and not sweat a bunch on a warm day in the air.

For drysuits. The air temp warms up, but the water temp is still waaay down there. You end up sweating like a pig in the drysuit, but what choice do you have? Bring lots of water!

It sure doesn't seem to be the most practical of boats.

One option is the Garmin gpsmap60:

http://www.garmin.com/products/gpsmap60cx/

Most models don't allow a download of charts, although the gpsmap60 does allow this.

I have a Garmin e-trex vista, which allows waypoints and route transfers, but not maps.

The general caveat is not to use these as a substitute for good map and compass work. Actually, the single best thing I've gotten out of the units is a continual monitoring of velocity. This is great for improving your forward stroke through direct feedback.

Units have been sometimes known to fail when they were counted on - batteries, dampness, lack of sattelite signals. Still, they can be fun to have on-board.

In the Globe today

[link:www.boston.com/news/local/articles/2006/03/14/3_uri_students_missing_after_post_party_ride_on_foggy_bay/]

This was a rowboat, with three students going out at 2:30 AM after a party with 40 degree water temperature, no PFD's, thick fog.

I took the Solo course last year. The cert lasts for two years, and they also have an option to squeeze in the CPR cert.

I highly recommend it - in fact - I had a choking incident at work and had to do a Heimlich to clear a woman's trachea, not to mention other minor incidents - so this training is definitely valuable!

John H.

This, and Cape Winds...

I had to give a tour of my experiment to Senator Ted Stevens from Alaska. He's sometimes called "Yosemite Sam" - if you're on the other side of an issue from him, you can practically see steam coming out of his ears. My own view on drilling on the National Arctic Wildlife Refuge is that we should hold off on it until we have a more sensible national energy policy, but I wouldn't dream of saying this to the Senator from Alaska.

It's a tough problem - we say we don't want the problems associated with energy, but at the same time, we burn fuel like gluttons.

Many of the LNG ports suggested all would have negative implications for sea kayakers. I guess I would err on the side of having them in closer proximity to urban settings, since we have to face the fact that it's needed.

That might explain why I don't know my ACA number. I get very little or no information from them.

Rick Crangle sent me a bunch of URL's on waves - the two I found the most interesting for water waves are below:

http://w3.salemstate.edu/~lhanson/gls214/gls214_waves.html

http://research.haifa.ac.il/~maritime/depa...cean/lect18.htm

Thanks, Rick, and to all who attended the courses!

Best,

John Huth

I read somewhere the Rebecca Giddens (US olympic silver medalist in the slalom in Athens) did this one: stand on an exercise ball and have someone throw a medicine ball at you and toss it back.

I have to say that I have yet to accomplish the simple task of balancing on an exercise ball on my feet - but I thought y'all might get a kick of that.

Adam - pretty nice. I'm always up for some new moves.

There's also the wood-chop: basically take a medicine ball and move it in a diagonal direction from the foot to up in the air in a standing position. 3 reps per side at 60 seconds each.

Another one, which is good core/balance is this: kneel on a swiss exercise ball (feet not touching the ground, so you're balancing on the ball) - take two weights (I use 5 lbs...but whatever) - and use a paddle stroke motion - with or without any diagonal core rotation. Go for 100 or so rotations (but you have to work up to it).

The good thing about this is that there are all these muscles that are used for fine motor coordination for example, in surfing - when you're doing the balancing, but also paddling at the same time.

Remember - keep the ferrous metals away from the compass!!!

The course is 10-12 tomorrow, followed by Bob Budd from 1 till 4 PM.

John

OK - for tomorrow's weather/wave course, we'll start out with a discussion of observations you made over the last two weeks. I hope some of you noticed the classic warm front moving through with the high winds and rain. When I saw the high cirrus clouds moving in, I was thinking "oh boy...this is perfect timing!"

I'm going to spend a bit more time on thunderstorms and gust fronts because this is a major issue that kayakers can face and a big potential hazard, then move onto waves.

Someone asked for the powerpoint transparencies - here they are. Note that my chart of barometric readings from October gives you an idea of what to look for in how fast pressure changes indicate fronts.

PPT of two weeks ago:

http://nspn.kates.org/2006/Huth-John/Bascom.ppt

PPT for tomorrow:

http://nspn.kates.org/2006/Huth-John/Jan_21.ppt

Web-browser version for tomorrow:

http://nspn.kates.org/2006/Huth-John/Jan_21/

Best,

John Huth