Advice needed using a MUF Delta 20cm

Calling all Budgie Boys & Gals and others....I need a bit of advice.

I have had two sessions on a MUF Delta 20cm and am struggling with the board pointing upwind even when planning which is self defeating as the board then comes off the plane.

I have tried the following:
1. Max Mast pressure by loading the harness.
2. Pushing off the front foot to bear away and with the rear knee bent and only my toes lightly placed in front of the rear foot strap (virtually no rear foot pressure).
3. Moved mast base forward 1cm, then tried moved mast base back 1cm.

I am using a Rocket 135 72cm wide with an Ezzy Legacy 5.8m and MUF Delta 20cm.

Any advice on correcting this would be much appreciated.

Thanks,
Sam

I was on a 20 Delta at Lilacs, Albany with JP SL66 6.7 NP Hellcat and when getting up wins for the NM i found that back foot out and in front of strap worked a treat. That was my first time on a delta.

I want to know how the Tribal SuperWeed compares to a delta, what do I buy? New XT Delta??!!??

I had my rear foot in front of the back strap and the rear foot pressure was a feather touch with the toes. Front foot pushing the board downwind and loading the harness at the same time. Very tiring work only to see the board fighting me to bear upwind.

I agree that a 22cm fin is the answer or should it be a 24cm?. Waiting to pickup a Delta XT 22cm from legless.

Depending on conditions I use anywhere from a 17-20 Delta at Budgewoi. Pointing up wind is always a challenge on a Delta unless it is really flat and you are fully powered up.

I'm not sure how confident you are but what I find works really well is the following.
1- Back foot out of straps but pushing hard up against front of rear foot strap to drive board up wind
2- Tilt sail aft and windward by;
3- Hold on to mast below boom with front hand.

I find this keeps me on just on the plane, even on very small boards (44cm CA speed board) but allows me to drive upwind better. Not sure if this is technically correct but works for me.

Interesting topic.
I've got into some funny habits to cope with being underfinned with deltas at Budgy. I've used a 20cm on a 75 wide board and a 7.8m. Couldn't put any pressure on it ( I have a low spinout tolerance.. a couple of spinouts and you need a swear jar and I'm over it)
I just used minimum pressure on the back foot and dipped the leeward rail. Works best overpowered as I also tip the rig towards the eye of the wind and ease it out a bit. I can shoot upwind with that but don't go as well underpowered or normally powered using that technique..I'm not the fastest sailor upwind but I get there.
I also sail with the backfoot out ot the strap a fair bit when not powered up a lot although i don't know if that's related.
I just bought a 22cm delta XT for that board and wow what a difference! I can push on it like a normal fin and sail more normally.
I also use a 19 delta with the 90ltre and 7m sail so I really need to get a larger one for that eventually.Much less effort and more fun factor!
I started speed sailing at Budgy on waveboards ..now they were a pain to get upwind. I used to think there was problems with the sailor but the first day i got on the slalom board wow! So easy!

I got 32.99 on the old beat up pocket wave before I upgraded to older slalom.. slow for the guys but was fast for me back then.

For that size board and sail combo would probably need a 24cm delta or Kestral Black Project fin , the best would be to use a 50 deg Black project fin and stay out in a little deeper water and save the 20cm fin for a board around the 100 litres .

I wrote this piece for Windsurfing Magazine ( Germany ) a few years ago ( not sure if it was ever published) in conjunction with Dietrich Hanke at Maui Ultra Fins who supplied the technical data. Hopefully you might find some of it helpful :-)

I get asked a fair bit 'Which Delta size and foil shape should I choose.'
This is not an easy question to answer. So welcome to Delta for Dummies.
There are three foil shapes each approx 1% different in their foil thickness to chord ratio. The thickest is the Ride, the middle is Slalom and the finest is the Race.

All fins are a trade off between lift and drag. We all know drag makes you slow, but what's the deal with lift? Why is lift so important? It is the very first requirement of your fin that it generates enough force(horizontal lift) to balance that generated by the sail. Therefore big sails need big fins to generate big horizontal lift.

If your fin dies not generate enough force to counteract the sail your upwind ability suffers and in the very least you will sail with greater yaw and drift.(crabbing sideways).
Pointing your toes so that board is not horizontal but more tilted to the leeward rail results in the fin not being vertical either. All if a sudden your fin is now spending some of its force lifting vertically. That is lifting the tail of the board. (Taken to extremes this results in 'tailwalking' ) This in turn not only creates more lively feel to board but lessens drag from board itself. This is important because the board is responsible for 60% of total drag, whereas the fin only contributes 15%. The remaining 25% from sail,rig and sailor.
So it makes sense to decrease drag on board at expense of increased drag from your fin.The advantages of increased lift are many.
Increased lift gets you back up to the top of your speed run sooner, which gives you more time on your speed run which gives you more chance of connecting with a bullet and more chance at that exhilarating speed PB.
Increased lift enables better gybing with more chance of faster exits and as a result more fun and better alphas.

Problem solved, just get a Delta Ride that is about half the size of your standard pointer fin.

So why consider Slalom and Speed fins at all?

Because you knew it would not be that simple.
Lift is inversely proportional to drag Going fast requires less drag.
The lift vs drag ratio for any fin changes with speed. Generally speaking once the fin is at the high end of its speed range, the drag vs lift becomes proportionally worse. That is, when you are really hammering the drag is far more of a problem. At high speed the board is out of the water and so the proportion of the total drag coming from the fin is far greater.

Ok so the solution is pretty simple. If you want to go fast get a Speed fin, if you want good all round performance get a Slalom and if you want lift get a Ride.
Except it's still not that easy either.

The faster you go,the more lift and drag is produced. When using a Delta fin, the faster you go the less the influence the foil shape and the greater the influence of the total surface area of the fin on the amount of drag produced. For example, at high speed the Speed 20 is providing much the same resistance to the sail forces as a Ride 20 but with 40% less drag!

Ok problem solved.We get a speed fin and always sail really fast. That is fine as long it's really windy. To be clever, how about we use a 'too big' Speed fin to get my low speed lift? The extra length will reduce chop induced spin out as well. Problem solved right?

My issue with that solution is that the whole reason you are using Deltas is because you want to sail in heavy weed and or shallow water.(If this is not the case there are a heap of better fins you should be looking at.)
There is no point in having a fin too long to enable safe passage across the smooth shallows. Whether or not the ground effect is adding to your speed, I don't know, but if you are not in the shallows you will never know.
Secondly and even more importantly the longer the fin, the more weed your fin is cutting through. Deltas do this very well, but anyone who has sailed in the weed at Fangy's will tell you the effect of the weed on the leading edge of the fin. Simply put the weed creates substantial drag on the fin.I would guess far more than the foil shape.

The waters are now muddied nicely. But wait there is more!
The width of the tail and the weight of the sailor are potent contributors as well.
As the rail gets wider the leverage over the fin gets greater and hence more fin is required to stop the windward rail getting sunk.One solution is to move your back footstraps inboard. Experience suggests that Deltas are happiest in narrow tail boards.

How on earth do you then choose what size fin and foil to use? Well for me it's a blend of ability, technique and all of the above. If you have problems when using a Delta most of the time it's because you have not got the right fin for your particular blend of the factors above.

So when the time comes to choose the fin for your magic carpet ride. Consider the sail size, what pointer do you you use with that sail? Halve its length and you have the Delta length starting point.
Then accordingly increase the sizes by one cm each time to compensate for a wide tail, a bargearse and inexperience sailing with a Delta fin.

Now the hard part. You have to make the call on where on the scale of lift vs drag you want to sit.
Upwind ability, gybing ability, how weedy, how shallow, how windy and how fast all get plugged into the guesstimate equation.

Or you can ask me and blame me if I get it wrong.

Problem solved:-)