Tech: Simpilot boat autopilot simulator for Arduino

Ever since writing a Seatalk test program last year, I've been toying with the idea of developing an autopilot simulator. Well, after a few long flights and one rainy weekend too many, I have Simpilot, a simple boat autopilot simulator that runs on Arduino. Simpilot is controlled by a simple command language. For example, the following simulates sailing a triangular course around the intersection of the equator and the prime meridian (shown above):

add waypoint S1E1,-1.0,1.0add waypoint S1W1,-1.0,-1.0add waypoint N1E0,1.0,0.0set position N1E0set speed 10set mode Lgoto waypoint S1E1sim on
Commands are entered via the Arduino device's serial port. In the above example, the add commands define a waypoint for each vertex of the triangle, the set commands specify the vessel position, speed and pilot mode respectively, and the goto specifies the first destination. The simulation is started and stopped with sim on/off respectively. You can find this and other sample simulations in th…

Scary nautical place names

A quick glance at any nautical chart of South Australia reveals a bunch of scary-sounding place names that is enough to give any sailor the willies. Names like Anxious Bay, Seasick Bay, Misery Bay, Coffin Bay, Avoid Bay, Cape Catastrophe, Wreck Beach, Thorny PassageBog BayWreck GullyThe SnaresThe ScrapersFoul Bay, and Danger Point.

Clearly Captain Matthew Flinders endured a worrisome time during his 1802 circumnavigation of Australia. Within rapid succession he named Anxious Bay (11th Feb), Coffin Bay (16th Feb), Avoid Bay (17th Feb), Cape Catastrophe and Thorny Passage (21st Feb). Cape Catastrophe was the site of the capsizing of one of their boats, which sadly resulted in the loss of 8 crew. Coffin Bay, on the other hand, has nothing to do with the deceased; it was so named after Admiral Sir Isaac Coffin. Danger Point was named earlier (7th December 1800) by Captain James Grant en route from England to Sydney, who incidentally is the inspiration for the character in Patri…

Sharks need your help

How many times have you read about a shipwreck, only to read about a shark attack in the next sentence? As if the prospect of death by drowning is not bad enough, our minds rush to contemplate more gruesome endings. We humans are a fearful bunch and, in particular, we seem to possess some primordial fear of big beasts, especially those with sharp teeth.

Perhaps that is why on every continent where megafauna did not co-evolve with homosapiens, our ancestors eliminated them shortly after encountering them. For some somber reading, read The Sixth Extinction: An Unnatural History.

In the 1800’s we turned our attention to the seas and did our best to wipe out the ocean’s megafauna, starting with whales. The whales are (mostly) safe from human slaughter these days, but many large ocean species lack such protection.

Which brings me back to sharks. According to the journal Marine Policy we kill about 100 million sharks per year. That could well be conservative though with the upper range nor…

Tech: Installing a seawater pump

After running out of freshwater on one of my sailing trips last summer, I decided to install a seawater pump in the galley. Here’s the step-by-step installation process in pictures:

The first part of the installation has to be done when your vessel is out of the water, namely installing a thru-hull and seacock. I could have beached Arriba and worked at low tide but I decided to wait until her regular haul-out (top photo).

Personally, I don’t like drilling holes through hulls, so I got a professional to do it. The thru-hull is directly beneath the galley, in Arriba’s starboard hull.  This location ensures a short run up to the sink while also positioning the inlet well forward of the engine’s seawater cooling outlet. It was interesting to see that the floor of the galley hull is 10cm (4") below water level.
The plumbing is straightforward and you don’t need a professional to do it. Here’s what you’ll need. The seacock outlet is connected via ¾" hose to a raw water strainer, …

History: Time zones, Zulu time and the SS Warrimoo

I suffer from XTZT - Extreme Time Zone Traversal. Because I live in one time zone and work in another, I routinely cross time zones. Like most air travelers, I don’t give it much thought though. Time zones, like jet travel, are just a part of modern life. I only wish my body adjusted as quickly to a new time zone as easily as my gadgets do.
Time zones in their modern form are a recent invention, namely, a global system of standardized offsets from a reference time, known as UTC (from universel temps coordonné, the French for coordinated universal time). For convenience, time zones have names such as Pacific Standard Time (PST) or Australian Eastern Standard Time (AEST), but the true genius lies in the numbers, such as -08:00 or +10:00, which represent the hours and minutes relative to UTC. This system was first proposed in 1879 by Canadian Sir Sandford Fleming and implemented in 1883. Greenwich Mean Time (GMT) was used as the reference until the advent of atomic clocks and and the in…

The joy of winter sailing

If like me - and 4.4 billion other people - you live in the temperate zone, winter is probably not your prime sailing season. It seems that when autumn rolls around, most sailors turn their attention to land activities. Yet in many places around the world, there is often fun sailing to had even in the depth of winter.

Here are 5 reasons to sail in winter:
Reason # 1 You'll have more of the water to yourselves. This means fewer boats to dodge and more relaxed sailing.
Reason # 2 A corollary to #1, you'll share less of the sea’s bounty with others. The fishing is often better, and you’re more likely to attract wildlife, such as dolphins.
Reason # 3 Winter brings different wind and sea conditions and opportunities to hone your sailing skills in new ways.
Reason #4 Different weather patterns also opens up new anchorages and new things to see. For example, where I sail in South Australia, the winter northerlies open up southern Yorke Peninsula anchorages which are typically not av…

Fishing while sailing

Most anglers who fish from a boat usually do so while at anchor or drifting slowly. This can be a very pleasant way to spend a day on the water, but most sailors would prefer to be actually sailing. Fortunately there is another way, which lets you have your cake and eat it, namely trolling. 
NB: Trolling can also mean fishing by means of working a line up or down a stationary vessel, but here I’m referring to trailing a line behind a vessel while underway. Also, this is not to be confused with “trawling” which is towing a line with baited hooks attached at intervals, or towing a trawl net.
You may think that trolling is just an activity for slow-moving vessels, but that’s not necessarily the case. Certainly, if you’re trolling for trout on a lake, you’ll just be rambling along at a couple of knots. However trolling is also an excellent way to cover a large expanse of water at high speed. For example, if you’re trolling for tuna, go fast, as these agile predators can swim at 40 knots! …