You boat is not per se on the wrong course but it appears that it wants to be on that course because somewhere there is something very wrong with your tuning or sail settings.

If the wind is blowing at 15 knots and you can't even raise a hull than for some reason the rig is either stalled OR choked completely or it has been depowered like nobodies business.

Either way, it most likely a crew related error. Sorry, it is not that I wish to be harsh. But the biggest problem of this is that it will be hard to pin point what is going wrong.

Somewhere you are draining all the power from the rig and I expect that you are compounding on it by looking to other boats to much. What do I exactly mean by the last statement. Well, actually nobody starts a spi run very low. Good crews always power up and speed up by sailing high before gently steering down while keeping speed up. When this is done right you can steer low and go fast. BUT ! as soon as you drop of this gentle balance than you HAVE to start all over again. You just CAN'T sit there on the same course as everybody else (who still have speed) and expect to be accellerated back up to their speed. This is the balancing act when going down wind. Now if the sail setting is off to begin with than you may never reach the speeds that will allow you to steer down and sail deep. Such a situation will make you crazy as everybody seems to be flying downwind and no matter how you steer you can't match them.

Now I suspect that somewhere you are choking the mainsail (jib in to tight or slot to small), stalling the main (apparent wind coming from the side rather than front) or depowering the main far to much (far too much prebend, far too much downhaul, a hooking squaretop or a very under rotated mast). And these are just the major influences.

Upwind. This really sounds like choking or hooking to me. On the upwind in 15 knots of wind it will be difficult to sail with a sail that is too flat (flat is fast here). Well in the general sense anyway as you can make it too flat if you really go nutts on the the trim lines.

Where to start ?

Few tips that you may consider trying first :

-1- Seek out a fellow sailor at your club that does well on a modern boat (Don't any H16 or P18 sailors, they won't understand a modern rig like the Blades at all). Ask him to sail with you for an hour or so. And analyse the boat and your sailing skill together. Such a guys will immediately pick up on handling errors and advice you on how to improve on that. Any F18, I-20, F16 or A-cat sailor will do. When appropriet hand him the tiller and let him fine-tune the boat. Note the settings down when back on the beach and use these are a starting point for future sailing and work on handling first.

-2- Search and read all the trim posts on this forum. We have been over this trim/ tuning topic before a few times. Look for a basic setting and use that while working on your sailing skills. I will give a few pointers at the end of this post


Second step ;

It will be bit harsh to take but if the boat is DIW (dead in the water) and you are getting passed by old designs like P18 and H16 than it is the crew who is doing something VERY wrong. It is NOT the boat. No amount of error in the tuning can result in such a big lack of performance, only errors in sail and boat handling (Crew related) can.

Also try to use this to your advantage by finding a general trim (tuning) that is a decent compromise for all sailing conditions and sail with that all the time while FIRST working on your boat and sail handling skills. In time will get a feel for the boat and make relatively large improvements. With this newly acquired feel you can than later start to adjust the tuning and get a few more % performance out of the boat.

General settings for sloop sailing.

Upwind

Mainsheel traveller centred
Main sheet mild
Outhaul, when mild mainsheet tension, the foot must not be more than 2 inches of the boom in the middle
Mast rotation arm pointing to the middle of the daggerboard (not to shroud as is custom on F18's)
Tune both the jib traveller and jib sheet so that the jib does not flap (or curl on the luff) nor touch the spreader arms.


When you speed up you may gently pull the main sheet tighter, if the boat accellerates noticeably than pull it in some more. When she decellerates then sheet some out, when she stays at the same speed than just hold it where it is. Sheet for speed ALWAYS ! NEVER to keep the crew on the trapeze (sheeting for power). The last is a sure way to oversheeting the main and even stalling it.

Possible the jib will start to flap when you speed up. If you pointing angle is good (the same or a just little lower than the others) Than pull the jib sheet a little bit tighter till it stops flapping. If the luff is curling instead of the leech flapping than move the jib traveller just a little in, just enough to stop the curl. (curl here means the luff of the jib being pushed to WINDWARD as a result of the apparent wind backwinding the jib).

Every action should be small and measured and lead to more speed or higher pointing angles. If it doesn't than reverse the action.

If you are going slow and nothing helps than steer lower and try to speed up that way. Often when you have more speed you can head up a little bit again and stay there. So speed will help you point. Don't just steer the boat to the heading everybody else is steering when you are still DIW. The boat will NOT accellerate to the right speed like that. You will have to point lower to pick up some speed first before you can try to approach the heading everybody else is steering. If you ever decellerated to a point that you are going very slow, like when you head up to far for too long, than you have to start all over again. Keeping steering S-curves and try to stay on the egde.

Downwind.

Let out considerable jib sheet but not as much as to make it flap.
Mainsheet traveller out by indeed 6 inches
mainsheet just a little less tight than when going upwind OR the same. (never too loose)
Leave the outhaul in its upwind setting.
Release the mast rotation fully.
Hoist the spi
Sheet the spi and then HEAD UP to gain considerable speed

When you have achieved considerable speed than steer down in a controlled way. All the while the crew trims the spi so that it is very close to collapsing but never actually collapsing. The crew will be sheeting and working continiously, if he doesn't than HE is screwing up the boatspeed by not doing what he should do. The skipper continiously steers S-curves and optimizes speed to point low while NEVER letting the boat stall and fall of the groove and decellerating to a DIW state. If you do come in a DIW state than start ALL OVER again. There is no quick fix so don't try to find one; start all over. So head up high, power up, speed up and than steer down in a controlled way and continue your S-curves again.


Also learn to not look TOO obcessive to your competition. The crews that point highest on the upwind (and lowest on the downwind) with the best speed are all masters of riding the egde, riding the groove. They are very skilled in doing these S-curve manouvres. Speed is the key to pointing high and low. Without speed you WILL be pointing lower on teh upwind and higher on the downwind. If you are going much slower than you the difference in pointing angle can be very big indeed.

Sail boats are not car that just point to where you want to go and press the peddle deeper if you want to go faster. Sail boats require to be optimally positioned and coached into speed. Maybe it can best be compared to car racing on a bendy track. It is not always the driver with the most powerful car that wins here. Some drivers are very skilled at approaching a corner in the right way and keeping the speed up. Instead of just chosing the inside line and using alot of power to speed up again. As a result they go through the corner faster and come out out the corner faster. Sailing is very similar to that. You'll need to find the best way of steering that boat and finding that optimal groove.


Hope this helps