John Pennekamp State Park

Boot Key Harbor

On the way down here, we stopped at John Pennekamp State Park in Key Largo.  Although we have heard of this park for a long time, we have never been there before.  It turned out to be a very pleasant surprise.

The park has five diverse attractions.

1. It includes part of the barrier reef protecting The Hawk Channel.  Out there on the reef are moorings for day use where one can stop and snorkel.  We never stopped at one of those moorings because we always went past on breezy days when it is too rough for snorkeling. On calm days, we can find the same thing closer at Sombrero Reef, just 4 miles from Boot Key Harbor.
   
2. There is a coral aquarium at the visitors center.  That is what I'll talk about below.
   
3. There are nice nature trails.  Some taking you through the mangrove swamp.  Some taking you through the hammock forest.   We walked those and they were very nice.  Some Japanese tourists there at the same time were astounded at the big iguanas sitting in the tree branches above their heads.   We even ran into a family from Sweden out in the mangroves, and we shocked them when they found that we could understand what they were saying.
   
4. There is a basin with moorings and a marina with slips, and a nice beach.  It looks very nice, but according to our friends, it is too shallow for cruising boats to get in to.   Too bad.
   
5. They have glass bottom boat tours.  They weren't operating when we were there, but I suspect that the tour might be lots of fun.

Our previous encounters with coral were in the Virgin Islands.  I snorkeled at St. Croix in the early 1970s.   We also snorkeled in the British Virgin Islands in the mid 1970s.   We returned to the BVIs in the 90s but we were saddened to learn that almost all the coral we saw before was dead.  Today, it is incresingly difficult to find heathy coral at snorkeling depths.   Belize in The Atlantic and the Great Barrier Reef in Austrailia come to mind, but those are very hard to get to.

Therefore, I was delighted to find wonderfully healthy coral in the Pennekamp aquarium.  Someone did a great job there. The surprise benefit was that in the aquarium setting, one can spend a lot more time peering at the coral and admiring their beauty than is possible when you are diving.  It can't quite match the marvel of diving on a thriving reef, but it was close.  Those corals are fascinating creatures. Hats off to John Pennekamp.

If you travel to the keys, a stop at John Pennekamp park is well worth your while.

I'll blog my own pictures soon, but for now here are a few pictures of the park I found on the Internet.

Pipe Dream

Boot Key Harbor

Many larger boats used on-board diesel generators to charge their batteries.  Those things are very expensive, a maintenance nightmare, and worst of all, extremely noisy.  Being shut up in a boat together with a running generator sounds like a minor hell.   Despite that, a trawler owner in Vero told me that he runs his diesel generator 6.5 hours per day.  Another trawler moored near us in Boot Key Harbor seems to run his 12 or more hours per day.  Ay ay ay.

I could get on a soap box and sermonize about conserving power, but I won't.  At times in the past when our batteries were in poor condition, I had to run our generator as much as four hours per day.  Recently, with good batteries and sufficient solar panels, I think we run the generator as little as 3 hours per week.

The problem is not the energy use per se, or the generator per se, but rather the physics of lead acid batteries that can accept their final charge only very slowly. My pipe dream, and no doubt the pipe dream of those trawler owners, is for a device that would allow us to capture and store all the energy the engines can make for only a short running time each day.   Let me analyze the dream from an electrical engineer's perspective.

Our daily electric energy use is on the order of 50 amp-hours per day.  At an average of 12.5 volts, that amounts to 625 watt hours per day.  Let's say 1 kWh per day to be generous.  My diesel engine is rated at 37.5 hp which is 28 kw.  Therefore, one might think that I could run my engine for 1/28 hours (2 minutes) per day to make all my energy.  But I can't do that for several reasons, the main one being that the batteries can't accept the charge that quickly.

My pipe dream is for a device about the size, shape, weight and cost of a car battery that could accept charge at a rate of 28 kw for up to 2 minutes, and then trickle the energy out to charge my lead-acid batteries at an average rate of 167 watts for 6 hours.   The obvious choice for doing that would be a capacitor.  There is no theoretical ceiling on the rate that capacitors can accept charge.  Using clever electronics design (which I have not done yet) they could discharge that energy at a rate ideally suited for lead-acid batteries. The big question is how many capacitors would be needed?

1 kWh = 3,600,000 watt-seconds.   3,600,000 watt-seconds @ 14 volts = 257,000 ampere-seconds = 257,000 coulombs of charge.  257000 coulombs @ 2.5 volts or roughly 100,000 farads of capacitance.  (I use 2.5 v instead of 14 v because that is the maximum voltage rating of ultracapacitors.  Several capacitors in series would be needed to make 14 volts.)

When I was an electrical engineering student in college, we measured capacitors in micro-farads. Today we have super-capacitors and even ultra-capacitors measured in farads.  So the technology of making capacitors has improved by a factor of one million.

I went online to checks prices and specifications.  Twenty WIMA 5000F capacitors would do the job with a total of 19.5 kilo-farads, for a a volume of 0.7 cubic feet (about the size of two large car batteries), and a weight of 500 pounds, and a price of about $57,000.

Bottom line: the performance and prices of capacitors need to improve another factor of 10 to 100 before the pipe dream becomes reasonable.

Caveat:  My engineering skills are rusty, and I don't have much confidence in those calculations.  If any of you are able to double check them for me, I'll be grateful.  The main reference is here.
 
p.s. Put this in perspective with some of the more idiotic renewable energy advocates who think that they can use capacitors to store the energy of solar wind farms in quantities large enough to power entire states and countries.   That would take a capacitor somewhat larger than the moon.

Christmas

Boot Key Harbor

 

Libby is pretty good ad finding presents. She knows I love to learn, so she gave me a violin for Christmas. I've never even held a violin before, so at age 69 I'm starting from absolute scratch. That's lots of learning opportunity. Also, violins are small, light, and made of materials that corrode in the salt air.

She also gave me a pair of fancy black shorts. I'll save them for formal occasions such as weddings, funerals, Nobel prize ceremonies, cruisers pot luck dinners. And oh yes, now I have to add Carnegie Hall violin recitals to that list.

 

 

Merry Christmas.

Above: dinghy name of the year.

 

 

Subtropical Christmas

Boot Key Harbor

First, I have to apologize for letting so much time go between blogs.  The truth is that I joined a local gym and started going there for two hour workouts every morning.  That will surely help me get into shape, and it makes me feel good, but it does have side effects.   After my morning workout, I return to the boat on a high.  Then I eat lunch and lie down for a little rest and -- presto it is dark out.   The workouts leave me drained of energy to do anything else during the day.  I had a deadline for the Westsail newsletter last weekend and missed it.  I completely forgot about blogging.    I'm going to try juggling the schedule to work out late in the day.

But my real topic for today is spending Christmas in the tropics.   The weather this week is perfect.  Cobalt blue skies, moderate temperatures, gentle breezes, and a sun so bright that you must squint your eyes to go outside.  Coconuts floating in the water.  Dolphins and manatees swimming around.  Iguanas everywhere on land.  It sure doesn't look like Christmas, nor feel like Christmas.

Of course, we try.  Businesses in the town are decorated.  We had a parade of boats decorated with Christmas lights; very impressive (but sorry, I can never take night photos from the deck of a boat).  I walk around the past week wearing my Santa hat.  Libby bought a little 12 inch potted tree and decorated it with battery powered lights.  Still, it fails to feel like Christmas.

I think the bottom line is not the weather, it is the absence of small children.  The joy of Christmas for most adults has always been watching the joy of small children.   Oh well.  Last year we had a great Christmas at Dave's house.  John was there with his children, but they are no longer small.  They are nearly adults.  I guess that Libby and I have to wait it out another decade or so until great grandchildren start appearing.

But we still manage to have fun.  Saturday night we went to "Movie night in the park." they showed Jean Shepard's A Christmas Story.  That movie has become an American classic.  We really did enjoy nostalgic Christmas feelings from that.  Even better, all the kids in the audience squealed with delight when little Ralphie found out that he really did get his BB gun present.

Tomorrow, Christmas Day, we'll go to a pot luck dinner with the other cruisers from the harbor. That too will certainly be fun.

But what about you?   The crew of the sailing vessel Tarwathie wish you a happy (and Christmasy) Christmas.

Movie night in the park.  See Libby waving?

Confirming Info

Boot Key Harbor, Marathon, Florida

Sorry for the lack of blog articles.  I joined the local gym and started working out two hours per day.  That robs me of a lot of energy.  I also haven't adjusted my daily routine to compensate yet.

I wrote a few things recently that should be subject to verification.  Here it is.

Water Levels:  I wrote that the depths on the bay side of the keys seemed to be higher than normal.  I also wrote that the low tides in Boot Key seemed to vary substantially from year to year.  I found NOAA data specific to this location that validates both.

This is the very long term trend.  
I am most interested in the variations which seem to be about 6 inches

There is a seasonal variation here that I wasn't aware of.  
Why it varies, I don't know. 

The long term wiggles are very visible here..

I made a custom plot of low tides only.
0.0 is the average over 3 years.

It is true.  The winter of 2011, the low tides were nearly a foot lower than now.  Why should this be?  The NOAA site hints that it may be related to the famous El Niño oscillation in the Pacific.

Thinning of the blood: I've always used this expression thinking that it was folklore.  When you spend times in warm climates, your "blood gets thinned" meaning you adapt.   Now I learned that there is a basis in fact.  The hypothalamus regulates the body's thermostat, and it adapts to your local climate.  It goes under the very fancy name of hypothalamus adaptive thermogenesis.  Therefore, while your blood does not thin literally, it does figuratively.