The Nautical Blog

Boat Safety – Week/Lesson 4

In tonight’s class we were given a sticker for Emergency Radio Call Procedures to stick on our boat next to the radio, paired off in two’s and given a chart. 

With the chart, we were asked to read all the comments and find the distance scale. Then use only the sides of the chart to get miles, distance and base. This is because latitude (lat) measures equal distance on either side from the equator. Longitude (lo) does not. The equator is 0° lat.

for example: if you draw a circle and a line in the center horizontally, that becomes the equator. Latitude lines go from east to west and measure angular distances both north and south of the equator. The North Pole is known as lat 90° N and the South Pole is lat 90° S. The halfway point between either pole and the equator is either lat 45° N or S.

Longitudes (aka meridians) are run from both the north and south through the earth’s poles and measure angular distances east to west of the prime meridian, which passes through Greenwich, England and is designated as 0° lo. The reason for choosing Greenwich as the prime meridian dates back to England dominating the seas when lat/los were being determined. If you go west from Greenwich one-quarter of the way around earth you are lo 90°W. If you go east instead, you are lo 90° E. Half way around earth equals 180° (east and west are same spot). This is also the approximate spot for the international date line. Both degrees of lat and lo are divided into 60 minutes and each minute is divided into 60 seconds for measurement.

When using a chart, compass and GPS system, there is another factor you need to take into account. This is known as a variation.

The magnetic North Pole is not the same as the geographic North Pole. A compass needle doesn’t point to “True” North but to the Magnetic North Pole. The difference of several hundred miles between the two is what causes the variation.

Magnetic North is either east or west of true north depending on where you are, therefore the variation is either easterly or westerly. As you go further North, the angle widens giving a larger variation. Going south decreases the variation. Therefore, when charting without a gps, you must add or subtract the variation to get your accurate lat/lo.  (note: GPS systems make the corrections for you)

Next, we were given lat/los to find specific destinations. The chart we had was for Martha’s Vineyard and Block Island:

lat 41.21.19 & long 70.50.26 – you’d be off Gay Head Fl G 4 sec Gong

lat 41.26.29 & long 70.50.13 – you’d be between Pasque1 Island and Nashiwera Island

lat 41.30.50 & long 70.50.00 – you’d be at Bell Mo (A) – safe waters

National Oceanic and Atmospheric Administration (NOAA) is the organization who produces these charts for both government and commercial use.

Tidbit – lightning temperature is 3000°f

Global Positioning System (GPS) – needs 3 satellite signals to give a recreational boater their current position. There are two levels of accuracy:

  • one for the boaters (provides accuracy within 15 meters (49.2 ft) or less than 95% time
  • one for the government

A newer system is called Wide Area Augmentation System (WAAS). This has land based signals which bring errors down to 8 or 9 feet.

Tidbit:  Torpedo markings on charts means stay away. If you touch one, it won’t blow up, but it will put a nice hole in your boat’s hull.

Buoys – they are all visual and there for multiple reasons. One reason is to confirm on the chart where you are, tell the coast guard if need be. But beware – you’re lookout may get bored and not be looking out for you.  There is about 30 minutes in the evening before light is gone where everything loses its color and looks grey.

Numbers on buoys are white and white light means your under way. If traveling in the fog, take out your hand compass for the charts and be quiet. Listen for the sounds and count the beeps. On the chart if you see MO (A) – you’re in safe waters and you’ll see a light flashing morse code for safety.

A must have book for distance coastal boating is:  Coast Pilot by Commerce.

Tidbit: Intracoastal waterway (ICW) starts in New Jersey.

Don’t go into swimming areas – you kill a child and your life is OVER!

Sounds – Signal System You’ve Gotta Know:

1 toot (.)   – I intend to pass you on my port side (in the US if somebody does this and you agree – then give them 1 toot back. If not, give them 5 toots)

2 toots (..) – I intend to pass you on my starboard side

3 toots (…) – I’m going backwards

5 toots (…..) – Don’t do that – it’s dangerous

Using horns in restricted visibility –

you may hear a long blast every 2 minutes, this means power vessel is under way

two blasts every 2 minutes, means power vessel underway but not moving (this boat is not connected to the land and not making headway either)

a dash and 2 dots is a vessel under command or towing – sounds like a D

a dash and 3 dots is a vessel under command and being towed – sounds like a B

a dash and 4 dots is a pilot vessel that’s towing

2 dashes and 4 dots is a pilot vessel that’s stopped (possibly tied up to another boat)

blast horn constantly if stuck in the water

Finally, 4 toots (….) – International rule for backing up – like in Ft. Lauderdale and North River

homework:  chapters 8 and 9 

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