Challenge: How do you solve this?

[David M]

Zach,
Its all celestial navigation and it is cool stuff to learn. Some say it is worthless knowledge, but I disagree.

[Pelagic]

Well done Hellosailor……Your solution is correct but a bit rough for full kudos … however you do make up extra points for homespun solutions which work, so well done.

David M you were more on to the line of thinking that I have as on long passages going north and south….Gyro error was checked that way and latitude adjusted (High or Low)

Zach, checking compass error using “Heavenly Bodies” is done by what is called Azimuths or Amplitudes
Using Azimuths a sextant is handy and if I was crossing the pacific I would like to have one and know how to use it.

You can read this to get the basic idea how to actually do it
http://www.answers.com/topic/the-american-practical-navigator-chapter-17
If you Google…. Compass error …Amplitudes you can find these kind of tables to make it easier

http://www.csgnetwork.com/directnautamplitudes.html

[Lodesman]

David is right with using Polaris, but I think you'd have a lot of difficulty checking your compass with the midday sun, especially if you're in the tropics. Easiest method - use any celestial body for which you have a declination value during its rise or set. You'll need the nautical almanac and Nories nautical tables (or similar tables) - the Amplitudes table is entered with the declination of the body at rise/set and your latitude (this can be fairly rough). The value obtained from the table is added or subtracted from/to 090/270 depending on whether Dec is N/S and whether it's rising/setting. It's accurate to a tenth of a degree.


Kevin

[Lodesman]

This is the table you need from bowditch (table 22): http://www.nga.mil/MSISiteContent/St...ables/T-22.pdf

[Zach]

Thanks guys! Good information... always so much to learn.

[Pelagic]

Ok...who's next? Hellosailor??

Alright, I'll throw out another one. Again, think simple.
We were casting off for a day sail. It was me, the first mate, the Commodore of our yacht club, and another friend. Everything was checked off and ready. I put the Commodore on the bow lines, and our friend on the stern line. She let go the stern line, and climbed on board. The Commodore let go the bow line, and carried it back to climb on board, as I put the boat in reverse. Suddenly, the boat was headed sideways across the slip. I throttled back, put her in forward, and drove her back in. I had the Commodore tie the bow and stern lines back off, and checked the rudder, the shift cable, and a few other things, but no problems found. We tried again, but this time, the boat would not even move. It took us about 15 minutes to diagnose the problem.

[Charlie]

Bow line attached to the dock and boat?

[Charlie]

Here is another one. When Kai's is resovled we can try this:

Time to leave the Northen terminus of Highway 101 Lund BC Canada. Admiral wants more water so we pull over to the water dock and I hear a strange sound in the engine. Actually it was the lack of a sound. No water coming from the stern. Manuvering among a bunch of fishing boats and yachts you are able to dock the boat before the engine over heats. Simple problem. Check the impeller. Lots of pieces. Back Flush the heat exchanger with the dock hose. Make a puzzle of the old impeller and make sure you have every piece. This is a new engine. B/c I didn’t want these kind of problems. Replace the impeller. Start up the engine. No water. Check the thru hull. Open. Check the original raw water strainer. Four fish. And a little pool of water at the bottom. Remove fish and some seaweed. Reseal strainer. Check sea cock again still open. Start engine again. Still no water. Check strainer. No water at all in strainer. Tighten all hose fittings. Still no water. Scratch my head. Ok lets call a mechanic. Parts store just sold their last impeller of my size. Wait till the next day for a spare. Mechanic does the same thing I did. Help him thru the process. Ok still no water. “Oh strainer needs to be primed.” Close sea cock. Prime the raw water strainer. Start engine. Ok it works. Off we go into Desolation Sound with a spare impeller. Motor works great. Anchor overnight. Next morning in a light rain we play in the reversing rapids. Two Bald eagles fight with three Golden Eagles over a fish caught in the rapids. Sky clears then rain. Lets leave a day early. Start the engine. No water. Check the impeller. One fin cracked. Locate all the pieces to the puzzle(impeller) and scratch my head. No mechanic to call here. What’s the problem? Hint -- was fixed with just a screw driver.

The bow line, and stern line were untied from the dock by the crew. Left tied to the boat.
Or, am I misunderstanding the question?

And Charlie, my guess would be a loose hose clamp on the water intake?

[CharlieCobra]

Originally Posted by Kai Nui

And Charlie, my guess would be a loose hose clamp on the water intake?

Shore power cable perhaps? Don't ask me how I know this...

My second post was a guess at Charlie's challenge, but no, mine was not the shore power. Good guess though. We checked that. I think Charlie may have the answer, but I just misunderstood his question.

[Pelagic]

Kai Nui if there is nothing mechanical wrong then something is still connected to the boat to cause it to veer off to one side.

Shore cable, water hose, TV connection etc… or if it is low tide you are connected to the bottom…ie aground!

or maybe a deadhead that is pinning you from underneath

[David M]

Were you at a very low tide where you did not have enough depth to get out of your slip?