Thursday, November 28, 2019

Emergency Calls

Here in the marine world, virtually all marine VHF radios have a "panic" button which sends out a distress signal *which includes your location*.

And that nowadays virtually all cell phones have GPS capability, the really obvious follow-on is this:  Why do not all cell phones have this same capability?  A single button press calls 911 *and includes your location*?  IPhones will already dial 911 if you press the sleep/wake button rapidly 5 times or more...  why not have the phone add the GPS location to the call?

This seems like a no-brainer to me.  If the 911 call centers need help in adding digital location capability, I am sure the Coast Guard would be willing to share their technology.  And if not, I guess the phone could always transmit the location via voice synthesis, but that seems awkward and error-prone.

If you think this is a good idea, please share it widely - your action may be the one that causes this capability to appear.

Sunday, November 10, 2019

Mizzen Rain Hood

Because our mizzenmast is stepped inside the cockpit, the cockpit enclosure must by necessity allow for the penetration of the mast.  In an attempt to minimize the amount of rainwater that enters the cockpit via the mast, the enclosure has a "sock" that goes up the mast a little ways and is tied around it.  Undoubtedly it stops most rain drainage, but a still significant amount gets into the cockpit, annoyingly to wet our trousers when we sit down.

An improved solution was called for.

The problem, in the rain, no less.
My first attempt was a simple, straight strip of vinyl cloth, mightily stretched around the cross section of the mast.  For obvious reasons, tho I was able to make it work, it failed to meet my aesthetics criteria.  (That is aluminum tape - I have extolled it's virtues before...)

First attempt: sloppy
The first reason a straight strip of vinyl failed to conform easily is that the mizzen mast is not a round cross section.  And the second is that the bottom of the strip had to accommodate a larger diameter than the top, due to the presence of the top seam of the sock.

Mizzenmast cross section

Well, this obviously called for the application of the lesson learned in Making a Mast Boot, with a minor modification.

First, we need to have a tapered hood, smaller at the top than at the bottom in order to accommodate the sock. I decided that tho the sock was about 1/4" thick (1/2", counting both sides), I should make the hood slightly larger so that the sock could easily fit up inside the hood, and to accommodate the place where the ends of the sock overlapped. I chose to make the bottom of the hood 3/8" larger on a side, or 3/4", counting both sides.  So, the tapered section needed to have a diameter of 3.75" at the top, and 4.5" at the bottom.

Next, the mast cross section is not round. Instead, I chose to view it as two half-round sections, joined by two straight sections.

Since I already screwed up one piece of vinyl, I decided to make a paper pattern this time, using freezer paper (eh, it was what we had...). Using the instructions in the mast boot post, I traced out an arc of sufficient length to supply pieces for both the front and rear of the mast. The arc for the rear of the mast I made extra long so that the ends would be able to overlap, and then I cut this piece in two. Then I cut out a couple of straight sections to accommodate the sides of the mast.

When joined together, the pieces looked like this:

From left to right, this is:
  • Rear piece, extra long
  • Side piece
  • Front piece
  • Side piece
  • Rear piece, extra long
The change in shape seems kind of subtle, but the paper pattern fit the mast perfectly when I tested it.

Taped to back of the vinyl
After testing the pattern, I taped it to the back side of the vinyl, traced its outline and cut it out:

Taa Daa!
And... DONE!
And now because the hood is tapered, if I need to remove the sock I will not need to disturb the hood because I will be able to slide the sock up under the hood when reinstalling it.

Wednesday, November 6, 2019

Salnick's Fourth Law

Any conversation between boaters will eventually turn to the subject of marine heads.

(See also: Salnick’s First Law
               Salnick’s Second Law
               Salnick’s Third Law
               Adam’s First Law)

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