Setting the Starting Line in Current
Tidal currents add a whole dimension to a sailboat race and equally so to race management. Setting a fair starting line in current is a difficult task for even the most experienced PRO and, as always, the results will depend on the skills of the entire management team on the water.
Before you leave the dock make sure you have a skilled pin boat team who are experienced sailors and knowledgeable of local conditions. (A couple of strong backs will be necessary as well.) Also, make sure you have assembled the proper equipment for the conditions. You should have anchors that are compatible with the type of bottom conditions, fitted with plenty of chain and enough rode for a minimum 4 to 1 length to depth ratio. Some conditions may warrant 6 to 1. (Local knowledge here is a must). The anchor and rode on the signal boat should also be checked to be sure it is equal to the task. Some type of sentinel arrangement for the rodes on both the Pin and Signal is a must. A competitor hung up on the anchor line at either end of the line will, at a minimum ruin a start or at worst result in damage to boats and equipment. I also like to place a buoy off of the pre-start side of the signal boat extended approximately 5’on a piece of PVC to discourage competitors from hitting the signal boat. (The owner of the signal boat likes this even more than I do!)
I prefer to use a boat with a flag and staff for the pin rather than a mark. As you will find setting a good line, in current, usually requires multiple attempts. By using the boat you have several advantages: 1) If you have fitted both signal and pin boats with sufficient rode, fine tuning of the line may be accomplished quickly by simply adjusting the length of the rode. 2) When the Pin needs to be reset in can be done much quicker. 3) The flagstaff can be positioned at such a height where the line sighter is not as easily blocked by an OCS boat. 4) If you are sighting from the pin it is very difficult to anchor the pin boat in such a position as to accurately sight the line over a pin marker. The longer the line the more difficult this becomes.
The PRO should plan to have the signal boat on station approximately 30 minutes or more prior to the start. It usually is a good idea to send the mark boats ahead so they will have good wind reads when the signal arrives. The PRO should select an area for the start that allows for the starting line and the course to be rotated based on the anticipated conditions, without moving the signal boat. Re-anchoring a signal boat in current is a time consuming operation and it is frustrating to the competitors. However, sometimes it is unavoidable.
Once the signal boat is anchored observe the strength and direction of the current, along with the wind direction. Observe the effect of the current on the boats sailing. You should have a tide chart and know the time when the tide changes as well as the time of maximum current for the area. Tide charts are available for most areas at boating supply stores.
Now that you are anchored you will typically be faced with one of three situations:
1) The current and the wind are coming from approximately the same direction. In this case the current has very little effect on the positioning of the line. The line can be set square to the wind and the weather mark. The current will usually keep even the most aggressive fleets behind the line so you can set a line on the shorter ranges, typically one boat length times the number of competitors. This condition usually results in very few OCS boats, everyone getting in early, and results in the race management team drawing accolades for a great day of racing. It is also very rare.
2) The current and the wind are running in opposite directions: This condition also has very little effect on the position of the line. Usually the line should be square to the wind and weather mark or a slight favor (as explained in scenario 3 below) if the current is not exactly opposite the wind. However, due to the current pushing boats towards the line you will experience a great many OCS boats and potentially general recalls. In these conditions it is usually best to lengthen the line to 1.5 boat length times the number of competitors to allow room for maneuvering. It may be best to display the “I” flag (or even a “Z” if it is a very aggressive fleet) on the first attempted start when these conditions exist. This will get the attention of the sailors and you will get a start off with only a few OCS.
3) The Current is running across the wind: This is the most common situation you will find and it is also the most difficult. This requires a lot of practice, patience and skill on the part of the line setter and the pin boat team.
Let’s assume the current is running across the course from right to left, the signal boat is on the right side of the line and the weather mark is to be rounded to port. In this situation it is necessary to set the weather mark anywhere from 5 to 10 degrees down current of the true wind direction to allow for the set the boats will experience as they sail the weather leg and provide a relatively square leg. When this mark is shifted, the down current end of a line (the pin in this case) set square to the wind automatically becomes favored To allow for this try lengthening the line. If there is still a crowd at the pin drop the pin back slightly so as to create a slight signal boat end favor. The stronger the current the more you may have to favor an end.
This is a very inexact science and will require practice. The most important thing is to watch the sailors. If they are piling up at one end obviously it is because they perceive it as favored. As soon as you see this occurring (and assuming it is not because of a wind shift) hoist your “AP” and adjust the line so as to square it to the conditions. This should be done quickly and without hesitation (This is where those strong backs come in on the pin boat.) I usually anticipate that I will have one or two “AP”s if I have an extremely strong or foul current. This is also where your pin boat operators experience in anchoring comes under the greatest scrutiny in knowing where to drop the anchor so the boat (or mark) will end up where you want it.
Under these conditions your team will show its true colors. Under some conditions it is nearly impossible to get a perfect line, so don’t waste the day trying. In deference to a previous article there are some times where “ good enough” will have to do. A PRO should make that decision as to the amount of time being spent on fine tuning versus the acceptability of the line or the course.
Miles Martschink