Sunday, December 31, 2017

Speaker to magnets

It's exactly what it looks like, a field. A neutral place generally free of magnetic sources. I say this because there is no place on earth free of magnetic fields. We all live on a giant roundish rotating magnet. But in this empty field there isn't much. On our planet ambient background magnetic fields typically vary around 25 to 65 microTeslas. The extra microTeslas on you see on the meter are largely coming from power lines and other things around me. On the whole this isn't much and the local field is reading zero. However, a large green field isn't boat by any measure, and this is where we start.

Sunday, August 13, 2017

Jolting and Fleece

Can boat batteries shock you? The answer is yes and I can in an empirical way say this is the truth. The way you can test this is on a stinking hot humid day in Florida whilst in the bowels of the boat sweating like a pig have your wet arm come in contact with the positive and negative battery terminals. Will this kill you? No! Will  the shock hurt you? Not really. But in a cramped and confined hot space can it startle you causing your head to jerk up smacking the underside of the deck and let the wrench in your hand at the same time bridge the terminals causing notable arcy sparky stuff to briefly happen? Yep I know from personal experience this is very possible, and if there was hydrogen sulfide gas leaking from the batteries at the same time there might be a kaboom.

BTW the legal department on the fourth floor reminds me to tell everyone to not try to invent or test ways to have large batteries shock you. If you're going to try this anyway at least make sure you video it and use the revenue to help pay the medical bills. Although the voltage is low the amount of  the stored energy is large and the law of unintended circumstances can raise it's ugly head.

Monday, July 24, 2017


It never ceases to amaze me why people supposedly skilled in the art of building boats can do such stupid things. It could be in their minds it seemed to be a good idea at the time, or perhaps it's the delusion that their work is so good that it will never need to be touched again. So off we go on a modest photo essay of things I see that just drives me nuts. Our first case is corrosion protection.

Sunday, May 7, 2017

Template tempest

Rule number one: When you buy a four-foot open array radar, it ain't four feet. It's something else, and it's almost always longer. In sum, it didn't fit where it was supposed to go. This led to some interesting gyrations to find a solution. A number of problems had to be solved. The first was how to do some careful measuring of curved in space and time radar arch surfaces that were not perfectly symmetrical as you would expect of any hand made product. And who would be surprised to find out nothing on a boat is square and true? The second issue was measuring the swing of the radar array, and the third problem was the design of a cantilevered ledge to mount the radar on. But in the end the lesson here is that there is almost always a way to solve a problem. Oops did I just hedge my statement a bit?

Monday, April 17, 2017

Navpods and goo

Sometimes things in my truck look like garbage and there usually is some there. But often it's part of my tool kit. No it's not as pretty as my micrometer or as fancy as some of my electrical measurement gear is but nevertheless it does a great job of getting rid of goo. This plain piece of 1/4" acrylic is the remainder of a VHF radio install using a new plate that covered the much bigger hole from a older deceased unit. I have several similar pieces like this floating around in the bowels of the truck.

In the boating world there are two types of goo. Those that can be removed with the aid of solvents, and all the others. The others are what this unimposing piece of plastic is good for. I've pulled out a VDO chart plotter. I had never seen one before but they did exist at least in the past, and this one was long overdue for replacement. The new unit is a Garmin 7612 MFD and because of space issues I'm installing it in a PYI Seaview Power Pod. But I have to get rid of the goo first.

Saturday, April 15, 2017

The apoplectic wire pull

The DirecTV receiver failed. It was one of two on the boat. It was connected to a ten year old KVH satellite dome that was always on. Here is the catch. The existing receivers are legacy receivers and are no longer available. The newer SWM (Single Wire Multi-switch) technology receivers are available everywhere but not compatible with the existing dome. In theory you can add a powered Multi-switch to get around this. Given the age of all of the gear coupled with the mess behind the entertainment center with miles of unlabeled white coax cable it was decided to start anew. It seemed so simple at the time and then promptly went to hell in a hand basket when I tried to pull the new wiring.

Tuesday, January 31, 2017

Raymarine secret tech revealed.

I am often bemused by things I see on TV especially funky boating related content. Louis C.K. showed a photo he took of his chart plotter on some late night TV show talking about when he grounded his boat. It was from a classic E120 Ray system and I quickly was able to see the the safety contour was still set at the factory default of 66'. What this meant was all of the water that is less than 65' deep was all the same dark blue color on the chart. Set it to 7' and all water that is dark blue is.... you guessed it, is 6' or less, maybe much less so pay attention. Turquoise colored water is then 6' to 12', and white water is deeper than 12'. I sent Louis an email with instructions on how to set up his E120 better. I suspect he was too embarrassed to respond back to me.

So it bugs me that apparently Hollywood and TV professionals seem to know little or nothing about boats other than there should be women in bikinis aboard. The set up is simple. The shrewd NCIS New Orleans personnel suspect the boat they are on took a trip and a murder happened. The first antics not included in the little video clip was having the actor look at the waypoint list to figure out where the boat went. How could that be determined? Well in an abstract sort of way waypoint data does have a time stamp showing when it was created, but not used. The actor then decides to use Raymarine's top secret new "Back Trak 3D(™)" technology you will see for the very first time. Look out track points, you're a thing of the past. You're history, passé, old school and devoid of high tech 3D computer graphics.

The sad thing from the producer's viewpoint should be all the wasted money spent on pasting in a cheesy CAD model and zooming in on it when the track points could have been used for free and would have been realistic. I didn't buy the alternative "Back Trak" thing, but maybe it's real? Producers, got questions about real boaty stuff? Send me an email.

Sunday, January 29, 2017

The Electric Chair

I'm fairly sure this is R2D2's great grandfather and the image is iconic. It's circa about 1995. For those that are math challenged this is about 22 years ago. But this is really about the chair, or in this case two helm chairs. The chairs are beautiful and at the time most likely the best money could buy. Everything electrically adjusts. Headrests, position on the rails, and you name it is controlled by a panel of buttons on the side. Overall very cool if the electrical and mechanical stuff still worked. One sort of does, and the other not so much at all.

Very little documentation about these chairs still exist. After combing through the ship's papers and manuals I have a brochure, an unreadable wiring diagram, and parts list for things I can no longer purchase. Online is no help either. Time has marched passed these elaborate chairs.

Here is the second problem. The yacht is getting new teak flooring. Yep real teak, not some type of veneered plywood. So what do we do with the helm chairs?

Saturday, January 7, 2017

Wiring fuax pas

A couple of wires got swapped around during a new gear install and the subsequent damage was north of $7000. You had to look closely at the wiring to see what went wrong. This is the terminal block inside a Garmin GSD26 CHIRP sounder module, and the wiring is coming from an Airmar 2kW/3kW r109LH CHIRP transducer. This costly error was made when it was installed and resulted in the failure of two sounder modules, and a very expensive transducer.

Sunday, January 1, 2017

Captain Ralph's logs. The life of a delivery captain.

The life of a boat delivery captain is more often than not a easy or glamorous job. They can delivery new boats, not so new boats, and boats they wished they never stepped on the deck of. My friend Ralph has been doing this for a long time and as a consequence he has learned bad stuff on boats can and will happen on occasion. Engines crap out always at the worst times. They can also on occasion catch fire or sink. Navigation electronics and autopilots fail when you need them the most and the weather always has to be accommodated. The list of stuff that inconveniently breaks on a boat is almost endless. As a matter of fact it's a rare boat that everything on it is actually working. Ralph has to know the basics of almost every navigation system ever made, and he's a decent a 101 engine mechanic under duress.

As you can imagine over some metaphorical beers Whiskey Tango Foxtrot boat escapades flow right out of him. Ralph keeps a daily log of his trips, and through his eyes you are going to read his trip logs here on the Rant and the first one is fraught with problems. Did you know you can deliver a large boat on the water almost all the way to Tulsa Oklahoma? I didn't, and at times during this trip Ralph wishes he didn't either. Along the way Ralph adds in some some "Fun Facts" and comments about where he is.