I want to put a strobe light on top of the MOB pole I’m going to
build. I haven’t seen one I like, too heavy, too hard to activate
reliably, etc. I don’t want water activated because of false
activation and complication so I think I’m going to have to build one.

Any suggestions, comments, or especially links to suitable circuits
appreciated.

Back in the 70’s, there were these toys called eternal flames which
were a strobe and battery encased in a solid block of casting resin.
They would blink for years so it shouldn’t take much of a battery to
provide a night’s worth of flashing. I’d like to build something
similar, with a Normally ON magnetic reed switch so that the whole
thing was totally watertight and insulated from the elements. The unit
would then be kept off by a small magnet on a light line attached to
the holder. The light would then go on as soon as the pole separated
from the boat with no other action required. All this would be tucked
up inside the cover for the flag that holds the top of the pole to the
backstay.

With a GPS MOB position, I don’t think much of a strobe would be
required. This is just to help the person in the water find the float
and not for guiding a miles wide search. A bigger strobe on the
lifejacket should do that job. It shouldn’t take much of a strobe to
guide a boat over a couple hundred yards. Any thoughts on this also
appreciated.

Another question:

I think the pole should be very closely tied to the horseshoe buoy I'm
going to throw over with it. Too much line risks entanglement. I'm
figuring on just 2 - 3 feet of poly so it will float and not be long
enough to get into feet. OTOH, a long line would give the swimmer a
bigger target. I also have a lifesling for final recovery. I'm going
to try to set it up so just throwing the horseshoe overboard deploys
the pole and turns on the strobe.

Long line or short line?

BTW, I saw the link for the pole with the built in light. Too rich
for me. Besides, I like building stuff.


--

Roger Long

On Mon, 20 Mar 2006 12:41:22 GMT, "Roger Long"
wrote:

BTW, I saw the link for the pole with the built in light. Too rich
for me. Besides, I like building stuff.

Most people attach a floating strobe to the base of the pole with a
lanyard about 6 feet long. These strobes are readily available as MOB
lights, are waterproof, and have a gravity operated switch which turns
on when the light is upright. I think you'll end up with a cheaper
and more reliable unit if you buy a commercial unit as opposed to
rolling your own, even though it might be a fun project if you have
the time and expertise.

Attaching anything to the top of the pole other than a small flag or
streamer is a bad idea because it will tend to make the pole top
heavy.

"Wayne.B" wrote

Attaching anything to the top of the pole other than a small flag or
streamer is a bad idea because it will tend to make the pole top
heavy.

That's one of the reasons I'm building my own. I've spent a lifetime
making things float upright

http://home.maine.rr.com/rlma/Boats.htm

I want the light at the top. The swimmer with his eye one inch above
sea level is going to have a hard time getting to a floating light.

--

Roger Long

Roger Long wrote:
I want to put a strobe light on top of the MOB pole I'm going to
build. I haven't seen one I like, too heavy, too hard to activate
reliably, etc. I don't want water activated because of false
activation and complication so I think I'm going to have to build one.

Any suggestions, comments, or especially links to suitable circuits
appreciated.

Back in the 70's, there were these toys called eternal flames which
were a strobe and battery encased in a solid block of casting resin.
They would blink for years so it shouldn't take much of a battery to
provide a night's worth of flashing. I'd like to build something
similar, with a Normally ON magnetic reed switch so that the whole
thing was totally watertight and insulated from the elements. The unit
would then be kept off by a small magnet on a light line attached to
the holder. The light would then go on as soon as the pole separated
from the boat with no other action required. All this would be tucked
up inside the cover for the flag that holds the top of the pole to the
backstay.

With a GPS MOB position, I don't think much of a strobe would be
required. This is just to help the person in the water find the float
and not for guiding a miles wide search. A bigger strobe on the
lifejacket should do that job. It shouldn't take much of a strobe to
guide a boat over a couple hundred yards. Any thoughts on this also
appreciated.

Another question:

I think the pole should be very closely tied to the horseshoe buoy I'm
going to throw over with it. Too much line risks entanglement. I'm
figuring on just 2 - 3 feet of poly so it will float and not be long
enough to get into feet. OTOH, a long line would give the swimmer a
bigger target. I also have a lifesling for final recovery. I'm going
to try to set it up so just throwing the horseshoe overboard deploys
the pole and turns on the strobe.

Long line or short line?

BTW, I saw the link for the pole with the built in light. Too rich
for me. Besides, I like building stuff.

My last one had an adaptation of the life-ring light found on most throwable
rings.

It was attached to a plstic collar at the top of the pole, and a magnetic
clip/switch of the plastic horseshoe push-on type kept the light from being
lit. This clip had a thin line attached to the rail so that when the pole
was deployed, the clip detached from the collar and the light came on. The
whole thing was small and extremely lightweight. A small battery was housed
beneath the light base, and kept the light going for about 40 minutes. The
bulb was only about the same as a toy flashlight bulb, so had low current
drain.

There must be some of these around in chandleries surely?

Dennis.