17 August 2010

PLB problem and modification

I have been using a Personal Locator Beacon for a few years.
While Australian Maritime laws require that I should carry an EPIRB while paddling offshore (more than two nautical miles from shore in non sheltered waters) I find that for sea kayaking a PLB is possibly a safer unit to have in case of emergency.
I believe that a beacon should be carried on the person and be readily accessible in case of emergency instead of being stored below deck when kayaking.
Current EPIRBs are too bulky to be carried on my PFD.

I have my PLB attached to the back of my life jacket and is exposed to the marine environment, often submerged while rolling or swimming.

While the manufacturer does assure that my PLB (model GME MT 410G) is a waterproof and submersible unit there are several documented cases (that I am aware) of malfunction of the unit by water intrusion.

On a trip to the Whitsunday Islands our group had one GME unit activate by itself without any prompting by the user.
The PLB started to beep suddenly giving the same signal as transmitting an emergency call.
We were able to paddle to shore and had the presence of mind to quickly deactivate the unit by disconnecting the battery.
Here are the steps that we performed to disable the PLB:
To do so, the top cap had to be unscrewed and removed.
unscrewing cap
removing cap

After removal of the cap the plug that connects the battery was separated from the electronics.
removing battery connector
water droplets on battery
salt water present inside the PLB
At close inspection and careful analysis I noticed the small "O" ring under the central screw was deformed.
It appears to be a design flaw.
GME designed the unit to have the "O" ring under the screw under compression but did not create a suitable receptacle for the "O" ring to be housed and prevent lateral expansion.
So, after a while the "O" ring slips away from the screw's head and allows leakage. The faulty unit was returned to GME and repaired under warranty.
I was assured that it was an isolated case but after the recent reports of other GME units malfunctioning I have my doubts.
GME has not recalled the units nor updated the design.

I have therefore decided to address the problem myself and modified the unit to possibly prevent the same problem occur again.
The central screw on the cap is recessed deeply into the shape of the cap.
I simply cleaned the area and applied a liberal amount of polyurethane sealant (not silicone) to the cavity and worked it really well to ensure good adhesion of the sealant.

In a few years time when the battery of the PLB unit will need replacing there might be a bit of a problem reaching that screw but in the meantime I hope that at least my unit will possibly not malfunction there.

14 August 2010

Committed to surfing.

On a recent trip I was joined by a sea kayaker that likes to mix up the fun: surfing is as important to him as sea kayaking.
While he is a good sea kayak surfer he also likes to surf with his surfboard.
Meet Adrian:
Adrian (c)
His passion for surfing goes back to his childhood.
Since he has moved to the South-East Queensland area he no longer lives right on the beach.
Surfing at the local spots at Gold or Sunshine coast does not bring him the experience that he once had when young.
He does not mind the surf, actually quite good; he laments the crowds that he has to share his waves with.
So he decided to experiment with combining a sea kayak trip with board surfing.
He rigged a special holder on the back of his kayak for his compact ultralight surf board.
surfboard transport (c)
The trip to one of his favorite non crowded spots took a few hours of paddling.
His board seemed well secured and posed no problems in the 15knots wind and small waves washing over the deck.
There was a slight increase in weather cocking but nothing a bit of skeg could not correct.
The reward however was worth it...
Adrian surfing_2 (c)
There was not a single other person in sight; and no jet skis either!

The waves were crowded nevertheless.
A large pod of dolphins wanted to share the same fun.

However all was good and no "turf wars" were sparked by Adrian's presence among the locals.
I stood on the rocks watching Adrian having fun, jealous of his skills.

02 August 2010

Technique: reverse surfing

After the recent training with Queensland instructor Craig McSween, I gained more confidence in the surf.
Craig taught me how to land on the beach when the waves are bigger and one technique that he advocates is to reverse in, with the bow pointing out at sea.

His teaching calls for paddling your kayak backwards between the waves while forward paddling as waves roll in. The bigger the wave the more forward paddling/speed required to avoid the steep ones pushing you back.
In case my timing is out and a larger wave is approaching at the wrong time, he suggested paddling back out against the wave to brake the speed the wave could generate on my kayak.

However I wanted to know what would happen if I intentionally paddled with the wave, in reverse.
I wanted to surf them instead of just landing safely between them.
Reverse surfing is similar to forward surfing but the weight transfer is opposite.
To prevent pearling (burring my kayak's end in the water) I leant forward to the bow and un-weighted the stern.
It really works on small waves and after a few runs I was having great fun.
To push the technique further I then tried to actually lean back and bury that stern.
As predicted the kayak pierced the water's surface, the stern dived and I was pitched up in the air.

PS SEP10: this video was published by Rapid Media here