Thursday, February 22, 2007

Downwind in Tacticat

So the race is going pretty well. You made a good start, did well on the beat by watching the wind and heading for the side of the course with more pressure, found a good lane and sailed the whole beat in clear air, stayed out of trouble by avoiding the idiots, bots and other general mayhem, avoided getting trapped on the port tack layline, judged the starboard tack layline perfectly and rounded the windward and offset marks with the leaders.

Now you're ready to sail the run and you've come to Tillerman's blog to seek advice. What? You must be joking.

Sure. There are places to be gained and lost downwind in Tacticat. But it's the part of the game that I understand the least. So I will expose my ignorance by telling you what little I do know and perhaps some more experienced Tacticat players will tell you their secrets in the comments.

First some obvious things that apply to all three kinds of Tacticraft: cats, skiffs and Lasers...

  • If there is more wind on one side of the course go there.

  • Keep your air clear.

  • Sail the headed tack -- the one heading more in the direction you actually want to go.

  • Think about the leeward mark rounding. Which side of the gate will you round and how will you approach it for maximum gains. (More on this in the next Tacticat Tip). Unlike real sailboat racing the end of the run will come up much faster than you think. Or to be honest much faster than Tillerman can think.
The actual technique for downwind sailing varies a lot for the three different kinds of Tacticraft.

1. Tacticats. Tacticat catamarans are boring. (Or am I missing something). Head down to the "sail by the telltales" course by hitting space bar. Is there any more to know? As I said, Tacticats are boring.

2. Tactiskiffs. Tacticat skiffs are the opposite of boring. They will capsize at the slightest opportunity downwind. So hoist the kite and prepare to swim a lot. In a blow the person who capsizes the least will win.

So what do I know about avoiding capsizes? Not much. The little flashing dots and the "Flip Prob" number of the display you get by hitting the "E" key will give you some clue as to how much danger you are in. If the hairs on the back of the neck are telling you that you are about to invert then try one of the following...

  • Ease the mainsheet.

  • Head down to a dead run.

  • Try sailing without the kite.

Beyond that I know nothing.

3. TactiLasers. Ahah. The most popular boat to race in Tacticat (and in the real world). To be honest the TactiLaser doesn't behave exactly like a real Laser downwind (except perhaps when there are real world waves). The best way to sail the TactiLaser is to start it planing and keep it planing while sailing as deep an angle as you can. Avoid excessive rudder movement. Use the space bar to bear away rather than down arrow or page down keys. Use the I or E keys to display your speed and keep it in the range that planes.

Sound easy? See you at the windward mark later.

Update: Apparently some of the above is crap. Check the comments for real expert advice.


JSW225 said...

The trick isn't to sail the deepest angle possible while planing, the trick is to still have the best VMG. Somewhere in the range of planing (roughly winds of 8.0 and higher) there will be an optimum angle which you are making best VMG. It is not the deepest you can go while planing.

Tillerman said...

There you are dear readers. I told you I knew next to nothing about downwind sailing in Tacticat. Thanks jsw225 for that Tactitip.

rock steady said...

I agree, downwind is the toughest leg in tacticat. It appears picking the right tack straight from the mark rounding is important. If all is even go port, so you can come into the mark on starboard.

Ant said...

All great comments. I find that if you're in a pack of boats as you bear off down-wind stay on the starboard gybe maybe 10 degs high than dead-downwind for about 10 secs, you'll find a few boats go high straight round the mark, see theyre not doing well, gybe and run into you on port! They get the penalties and it clears the air a bit around you for you tom concentrate on the things Tillerman etc have just said

aestela said...

Unless there is a bug somewhere in the code (quite usual) once you are on a plane the best VMG is the green line angle (the deepest possible) UNLESS:
- There is an important windshift because VMG to the finish is not real VMG
- Going to ddep can take you out off planing (if speed goes lower than 8.8)

Tillerman said...

Hmmm - seems like we have three different theories of how to sail a Tacticat Laser downwind.

a) Me. As deep as you can while staying on the plane. But what do I know?

b) The Tacticat author. Sail the green line (unless there's a bug).

c) jsw225. Optimize VMG. Of course this one must be right but the real question is whether this is always the same thing as (a) or (b) or sometimes something else.

My head hurts. Seems like I need to do some controlled experiments to work this out. This is getting almost as complicated as sailing a real Laser.

aestela said...

in Tacticat, sailing as deep as possible is almost the right answer for lasers, but polars have arificially be defined to be just a little better 5 degs away of wind: the green line, the line where VMG is maximized.

We all aggree there, but VMG is usually referred to the wind direction (and always in Tacticat).

If you have a, say, 40 deg shift going to the finnish you SURE would choose the angle that takes you there sooner, and that can be a broad reach, less distance and more speed. In that case you would not chose the VMG optimized angle (off the wind) but the VMG to the finnish.


And now that we're at it. DW sailing tacticat cats is one of the funniest things in Tacticat.
And that is so because the blanketting effect for cats has been unrealistically enhanced. Giving chance to the boat that is behind and allowing for quite interesting fights.

JSW225 said...

I just got out to do some experimenting on a laser field by myself. At about 135-155 angle from the wind, the VMG peaks. Past that it drops. Now, if the wind speed is fast enough, you can sail the green line on a plane to get a fractionally better VMG. This value seems to be around 11.0 . Any wind speed less then this and the laser will come out of the plane for sailing so low. The difference in VMG is small between the green line and the angles I described. I'm talking about .1-.4 VMG faster.

Tillerman said...

Yeah - I just did some experimenting in around 12 knots. In this wind you can sail the green line without coming off the plane. Some times this gave the best VMG and some times sailing that 135-155 angle gave the best VMG. Some times it was the same. As you say jsw the difference is only a few tenths of a knot at most.

Tillerman said...

On the other hand in 10.4 knots the Tacticat Laser will plane all the time at that 133-135 angle to the wind and maintain a VMG of around 7.8 knots. But if you sail the boat on the green line it will keep coming on and off the plane with a VMG oscillating between approx 5 and 8 knots - almost certainly with a mean VMG of well below 7.8.

29erTom said...

sometimes in light winds you can get planing by sailing an angle about 135 but can't maintain it. try bearing off ddw, you will drop of plane but gain big distance.

i used to sail as low as possible but staying on plane. now i sail about 137 if i can. depends on the boats around you.

anything above 12, no ddw and gybe staying on the plane.


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