Hi All from down under
Excuse my ignorance but how do I use a compass to advantage
when racing I sail an A Cat.
I know I can get a bearing on the top mark by sighting it
and getting a bearing but is there some way to work out
optimal tacking angles and or windshifts.

I also have a an onboard gps which I use for speed so I can adjust trim to suit etc..

So if someone can give a novice a few lessons on the above would be well appreciated.

Our club racing season starts this weekend so all fired up to get some adenalin back in the veins after a lousy winter.

Thanks in advance.

You can use the compass in a number of ways

1,You can find out if you are on a header or a lift as you'll have taken time before the start to find out how much the wind is shifting. You may have regular veers(shift clockwise) and backs (counter clockwise) over time or there may be a trend to veer or back

2, You may after time, know what your tacking and gybing angles are; the compass can assist you in tacking or gybing at the right time

Try getting one of the better books and lokk this stuff up.

You can gain solid data on what the wind is doing to your heading while under sail. On each leg, you can watch your heading change in headers and lifts and you can begin to really visualize the patterns in the wind from either geographical features or oscillating patterns. Once you learn to use a compass, it will give you another tool to "see" the wind.

You can also use it to determine how square the start line is and if one end is favored or not.

I don't use a compass, but the general idea is, you sail upwind on both tacks and check the headings on each tack. For simplicity, say the wind and weather mark are at 000, on port your heading is 045, on starboard your heading is 315.

After the start, if you're on starboard and get a lift, your number will rise. If it goes to 325, you're on a 10-degree lift. If it goes lower, you're on a header.

If you're sailing on a lake or bay, or in most coastal locations, you can use landmarks to achieve similar results (determining lifts and headers).

The main reason most of us don't use compasses is simple, we weren't trained that way. Many dinghy sailors and practically all big boat sailors use them, but those boats also lose less per tack and can gain more by tacking on smaller shifts. Also, there are all those numbers to remember. <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

We do have some cat sailors that do well with compasses, but they are also good enough that they would probably win without one.

Before you race with a compass, and especially GPS, check your class rules. For example, the Hobie rules allow compasses (including electronic), but not GPS.

Hope this helps.

Mike

The compass will indicate changes in your heading which more often than not is the result of changes in wind direction. However it only gives you information about the situation where you are on the course. To get the big picture you have to look around. The compass only provides one very small piece of the puzzle and if relied on to heavily can mislead you. My recommendation for someone just getting started in sailboat racing would be to ignore it. There are much more important skills to develop. Besides who wants to spend their weekend doing mental arithmetic.

You did not mention if you plan to use a tactical compass or a regular compass. The information given so far is right on. You could simplify by using a tactical compass, though it hurts the pocketbook more.

If you use a tactical compass you will be setting the tacking angles for your boat. While on tactical mode the compass will give you the wind angle based on your sailing angle. If you can tack and get the same reading on both sides you have your tacking angle set right. Then while you are on a port tack if the number goes up you are sailing into a header. On Starboard the number will go down sailing into a header. For catamarans tack on headers of maybe 10 degrees or so, unless you are near the layline and need to make it.

Dan