NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Setting a course when sailing into the wind.
From: Lu Abel
Date: 2016 Jul 28, 17:26 +0000
From: Lu Abel
Date: 2016 Jul 28, 17:26 +0000
Well put, Bill!
When tacking a boat you are inherently losing forward momentum because there's no wind energy being delivered to the boat while the sails are not filled with wind. Even roll-tacking is simply a way of minimizing the time when there's no wind into the sails.
In my experience (40 years of sailing, a few years of being a not very good racer) is that boats in a race tend to tack frequently across the lay line in order to guard against wind shifts.
Suppose you're on a particular tack and you get headed (ie, the wind shifts in the direction you're sailing which means you have to bear off -- head at an even worse angle with respect to your target). Imagine that you're following the "just two tacks to take me to my windward goal" idea, you've just completed your long tack in one direction, you tack onto the other course -- and you're headed! You have no alternative but to continue on this now not-very-good course to windward.
If, on the other hand, you've stayed fairly close to the layline, you can flop over to the other tack -- which is now headed closer to the windward target than previously!
Ultimately, there is no single, simple answer... As pointed out by others, it depends on the type of race, the type of boats, where the race is taking place, and a whole host of other factors.
From: Bill B <NoReply_BillB@fer3.com>
To: luabel@ymail.com
Sent: Wednesday, July 27, 2016 12:48 PM
Subject: [NavList] Re: Setting a course when sailing into the wind.
On 7/27/2016 12:23 PM, Graham England wrote: > Some of the guys who race pointed out that racers tend to do many tacks > and use the momentum of the boat to gain some distance into the wind on > each tack. > Does anyone do this? In a sense it is navigation, getting from point a to point B in the shortest time has always been a sailor's goal, be it commerce, cruising or racing. In your scenario one might sail one tack, anticipating a wind shift. Long leg vs short leg, cruising or racing. As to racing, it will depend on the type of boat and distance. VOR vs, match racing vs Club dinghy racing on your local pond. Match racing and Club racing are very much a chess match based on boat speed, wind shifts and the competition. It is very likely racers will do a series of short tacks upwind to stay in the middle of the course and cover those behind them when heading for the upwind (weather) mark. Sometimes the fleet will split tacks hoping for better wind on one side of the course. There is also matter of leverage. If you are leading the pack, you have none and cannot make a mistake. If you are at the tail end you have a tremendous amount of leverage and may try any "champ or chump" move you wish as there is no more last than last (short of a DQ for not finishing in the allotted time). In a port/starboard crossing a boat slight ahead take onto the same tack (port or starboard) forward of and below the other boat to "lee bow" the other and leave them in a wind backwash off the sail that does not allow the other to point as high, or slows them down so they cannot "roll" you. In terms of boat speed,especially in a mixed fleet racing under handicap, a decision on boat speed vs pointing is made. Pinching (high point but slow, aka heading) vs sailing lower at higher speed. Velocity made good (VMG) is simply cosine of the angle upwind/to the mark times boat speed. As you can imagine, seldom will a match or club race be two tacks from the start line to the weather mark. As a rule of thumb tacks take time and slow you down, so a racer does not want to tack any more than necessary. For dinghy racers there is something called a "roll tack" where moving the crews weight and manipulating the sail just so may have your boat speed coming out of the tack greater than it was going in. The racing rules do not allow for continuous unnecessary roll tacks to move upwind at a greater speed, continuous rolling of the boat, ooching, or pumping the sails to create you own wind. The short answer to your question is no, tacks take time.
