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<HTML><P><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=300><IMG height=225 src="http://www.sailnet.com/images/content/authors/sue_larry/060903_SL_Look-Ma,-No-Hands.jpg" width=300><BR><DIV class=captionheader align=left><FONT color=#000000><B>Having an autopilot on board is like having an additional crew member, with the added advantages that it doesn't eat your provisions and it doesn't grumble.</B></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE>We affectionately refer to our autopilot as “<I>Toonces</I>” after “<I>Toonces</I> <I>the</I> <I>driving</I> <I>cat</I>”, who starred on Saturday Night Live many years ago.  OK, it may sound a little immature, but we’re not alone. Cruisers everywhere have pet names for this very important and quite endearing piece of equipment. For many sailors the autopilot has become the absolute ideal additional crew member. It offers convenience, safety, doesn’t eat much, and it won’t drink all your beer!   <P>Regardless of whether you plan to circumnavigate the globe or daysail the bay, having an extra hand on board in the form of an autopilot helps ease the burden during shorthanded situations. The primary benefit of an autopilot to the daysailor or weekender is convenience. Instead of always being just the helmsperson, you’ll be able to tweak the sails and even eat lunch with two hands for a change. If you’re a couple out cruising, the benefits extend far beyond just convenience. This third crew member, the autopilot, helps to reduce the fatigue that can result from spending countless hours at the helm. A clear mind free from exhaustion allows you to fully evaluate impending situations at sea and render proper judgments. Sue and I believe that an autopilot is such an important piece of safety equipment for long distance cruising that we installed a second back-up unit onboard <EM>Serengeti</EM> just prior to sailing to Bermuda last year.  </P><P><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=300><IMG height=225 src="http://www.sailnet.com/images/content/authors/sue_larry/060903_SL_Course-Computer-i.jpg" width=300><BR><DIV class=captionheader align=left><FONT color=#000000><B>The course computer, which is the brains of the autopilot, is usually an independent component that is mounted below decks.</B></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE>There are several different types of autopilots to choose from out there. Although these autopilots vary in duty and suitability, most consist of four basic components plus a drive unit. First, there’s the course computer. The course computer is usually a stand-alone component that is mounted below decks, but is sometimes built into the display unit mounted in the cockpit. This computer is the brains of the autopilot and does all the thinking and processing of information while communicating and directing each individual component of the system.  Kind of like the conductor of a symphony.   <P><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=300><IMG height=225 src="http://www.sailnet.com/images/content/authors/sue_larry/060903_SL_CockpitDisplay.jpg" width=300><BR><DIV class=captionheader align=left><FONT color=#000000><STRONG>The cockpit display allows the helmsman to engage or disengage the autopilot or to make adjustments in heading.</STRONG></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE>The cockpit mounted display provides the interface between the helmsman and the course computer and is probably the piece of equipment that everyone’s most familiar with. The display allows the helmsman to engage or disengage the autopilot or to make adjustments in heading. The cockpit display can additionally act as a repeater providing other navigational information along with providing the helmsman information regarding the angle of the rudder at any given moment.   <P>The autopilot’s course computer obtains its directional information by means of an electronic compass called a fluxgate compass. A fluxgate compass tracks your boat’s heading and sends this information back to the course computer. This particular compass is always mounted below deck in fiberglass boats and is positioned as low and as close to the centerline of the boat as possible.  To avoid magnetic interference and provide a true reading fluxgate compasses are located away from any large mass of metal like your engine or iron fuel tanks.   </P><P><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=300><IMG height=225 src="http://www.sailnet.com/images/content/authors/sue_larry/060903_SL_Commoncomponentsp.jpg" width=300><BR><DIV class=captionheader align=left><FONT color=#000000><STRONG>Although autopilots vary in duty and suitability, most consist of four basic components (rudder reference indicator, cockpit display, course computer, fluxgate compass) plus a drive unit.</STRONG></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE>The final component similar to almost all autopilots is a rudder reference indicator. This piece of equipment mounts forward of your rudder post and connects to the steering quadrant by an adjustable arm. The rudder reference indicator relays information about the position of the rudder back to the course computer.  <P>The most significant difference between different autopilots is the type of drive unit that each employs. If the course computer is the brain of the autopilot, then the drive unit is the real workhorse<SPAN style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA">—</SPAN>it’s what actually does the steering. When specifying a new autopilot, it’s important to choose the correct drive unit first, then select the other components that function correctly with that particular drive.   </P><P><TABLE cellSpacing=0 cellPadding=10 width=160 align=right border=0><TBODY><TR><TD><IMG height=2 alt="" src="http://www.sailnet.com/images/content/authors/bullets/black_1pix.gif" width=160 border=0></TD></TR><TR><TD vAlign=top align=middle width=160><FONT face="Arial, Helvetica, sans serif" color=black size=+1><B><I>"When choosing an autopilot drive unit for your boat you’ll need to first consider the type of sailing you expect to do."</I></B></FONT></TD></TR><TR><TD><IMG height=2 alt="" src="http://www.sailnet.com/images/content/authors/bullets/black_1pix.gif" width=160 border=0></TD></TR></TBODY></TABLE>When choosing an autopilot drive unit for your boat you’ll need to first consider the type of sailing you expect to do. Next, select a drive unit that will work with your existing steering system. Take into account the length and fully loaded displacement of your boat while going through this process. Autopilot manufacturers fortunately make this process fairly easy by providing us with all sorts of charts so that we can properly size the components for our individual boat length and displacement. If you are on the border line between two systems, we think you’d be wise to choose the more highly rated unit so that your autopilot won’t fail you when you need it the most.   <P>For daysailing, coastal cruising, or an occasional offshore jaunt in boats less than 38 feet, an autopilot that utilizes a cockpit mounted drive motor may be all you need. With this type of autopilot a motor is mounted to the outside of your steering pedestal and a belt, similar to a fan belt on a car, attaches to a hub mounted immediately forward of the wheel.These autopilots are relatively inexpensive and easy to owner install.  We would not recommend this type of autopilot drive if you have plans to do any extended cruising.  <BR><BR><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=300><IMG height=164 src="http://www.sailnet.com/images/content/authors/sue_larry/060903_SL_linear-drive-unit.jpg" width=300><BR><DIV class=captionheader align=left><FONT color=#000000><STRONG>The most predominantly used autopilot drive unit used on sailboats with cable steering is a linear drive, which uses a rod attaching directly to the steering quadrant.</STRONG></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE>If you hanker for bluewater sailing, or your boat is larger than 38 feet, your best bet is to specify an autopilot with a below deck drive unit. Below deck drive units can be Linear, Hydraulic or Rotary. These more heavily rated pieces of equipment are designed to stand up to the rigors of long distance cruising and if properly sized and installed will withstand the abuse of almost constant usage.              </P><P>On sailboats employing cable steering, the most predominant below deck autopilot drive unit is a linear drive. Linear drive autopilots use a rod that attaches directly to the steering quadrant. The boat is steered as a result of this rod extending or contracting to turn the quadrant and hence the rudder. This type of drive requires a very stout mounting base as the forces placed upon it can be considerable. Today’s linear drives are very quiet and quite energy efficient.  A benefit to these drives over the others is that if your steering system fails, you can still maneuver and steer the boat with your autopilot.    </P><P><TABLE cellSpacing=0 cellPadding=10 width=160 align=right border=0><TBODY><TR><TD><IMG height=2 alt="" src="http://www.sailnet.com/images/content/authors/bullets/black_1pix.gif" width=160 border=0></TD></TR><TR><TD vAlign=top align=middle width=160><FONT face="Arial, Helvetica, sans serif" color=black size=+1><B><I>"If your boat has hydraulic steering, you’d probably want to install a hydraulic drive unit for your autopilot as well."</I></B></FONT></TD></TR><TR><TD><IMG height=2 alt="" src="http://www.sailnet.com/images/content/authors/bullets/black_1pix.gif" width=160 border=0></TD></TR></TBODY></TABLE>If your boat has hydraulic steering, you’d probably want to install a hydraulic drive unit for your autopilot as well. A hydraulic drive autopilot is very easy to install. The drive motor and pump mounts into your existing steering hoses and pushes the hydraulic fluid one way or another to steer your boat using the existing hydraulic ram. We installed this system on a friend’s boat one time in exchange for a 4 hp outboard motor. Including the time to learn the system, the entire installation took about one day. <P>Although not always mounted below deck, a rotary drive can be the right choice for many sailors. If your boat features a large fiberglass steering pedestal you may be able to install a rotary drive unit for your autopilot. A rotary usually drive mounts inside the fiberglass steering pedestal and is bolted to the floor. This type of drive is well protected from weather and is hidden from sight. A chain runs from the sprocket of the drive unit up to a sprocket affixed just forward the existing chain sprocket inside the pedestal. Rotary drive autopilots use your existing cable steering system to steer the boat. This poses an advantage in that the drive itself isn’t subjected to extremely high loads like with a linear drive. With a rotary drive autopilot, though, if you lose your cable steering you will also lose the ability to steer using your autopilot.  </P><P><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=300><IMG height=225 src="http://www.sailnet.com/images/content/authors/sue_larry/060903_SL_Hydraulic-drive-+.jpg" width=300><BR><DIV class=captionheader align=left><FONT color=#000000><STRONG>If your boat has hydraulic steering, you’ll probably want to install a hydraulic drive unit for your autopilot as well.  The good news is that this type of autopilot is very easy to install.</STRONG></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE>We recommend that most boat owners install any piece of equipment including an autopilot themselves whenever possible. If you don’t feel qualified to do the whole installation, at least stay with the person you hire to install it and ask lots of questions. You’ll be amazed at how easily you can trouble shoot a problem just by logically checking through each component.</P>Here are a few things to remember when sailing with an autopilot. Remember to keep a good lookout. Autopilots steer well but they don’t see worth a damn. They also can’t anticipate waves or wind gusts, so sometimes you have to rush back to the helm and lend a helping hand. To get the most out of your autopilot it’s very important to balance your sailplan. For instance, if your sails are over-trimmed, your boat will suffer from weather helm and will be trying to round up into the wind all the time. Your poor autopilot will be straining as much as it can to keep you on course.  An autopilot that’s properly sized for your boat, suited to your steering system and intended use should last you for many years. Remember to treat it well, and give it a good name.  “<I>Toonces</I>” is already taken. </FONT></HTML>
 
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