Go Greg! Who says it will be easy? Its not and thats the main reason why we keep doing it probably. I'm glad you are past the initial exitment now and you've figured out that you have a formidable opponent and you wont beat it with row power alone no matter how fit you are. The equipment has changed significantly and if your old board is 290 cm long you are not 15 years behind, you are more like 25 years behind-late 80s , early 90s maybe. I have not been windsurfing then, but a friend of mine has a board from this era and I've tried it on a few occasions out of curiosity, so I have an idea. It is very different how you sail this 80s boards and you really are starting from scratch with the new equipment by having to do exactly the opposite of what you've been used to .
I dont want to overwhelm you with information, so I'll try to just give you a few if the most important IMO pointers and I'll recommend you to read and reread Peter Harts technique articles in Windsurf Magazine:
www.windsurf.co.uk/category/technique/peter-hart/
He has been in the sport from the beginning and has seen it all and aparently he has a lot of returning windsurfers in his coaching classes, so you'll find many references about how it has been before and how it has changed.
Part 1. Starting with your equipment- I have put the front footstraps on my Atomic all the way back and out and the back footstraps middle holes and out . I want to experiment by moving my front straps one position in one day , because I feel like they make me bend my front leg too much when cranking upwind, but I may be wrong on that.
I put the mast foot about 1.5 cm back from the middle for my biggest sail to unstick the nose a little bit and I put it in the middle and a bit forward respectively for my smaller sails for more control in stronger winds.
Fins: For wider then 70 cm boards -something like that: 9.0 sq m sail=50 cm fin; 8.5=48 cm; 8.0=46 cm; 7.5=44 etc etc
Rig: I put the extension on max setting for every single sail and downhaul to the max -untill the pulleys almost touch- for when nicely powered to overpowered and I release the downhaul just enugh to be able to stick my pinky finger between the pulleys for underpowered conditions.
Boom position is extremly important for how early the board will plane!!! Old timers seem to prefer low boom position but this is counter productive now. Place your board without the fin on a grass or sand and attach the rig to it, step on the board and lift the rig. The best boom position for overall powered sailing will be at your shoulder hight-remember to wich mark on the sail luff it corresponds and set up your outhaul at this boom position always. If you are severely overpowered lower the boom to your chest level and to your chin level if you are severely underpowered respectively.
Outhaul: 2-4 cm of positive outhaul is usually enough. Keep in mind that moving the boom up or down from its initial position effectively releases or applies outhaul!
Harness lines: You need to find the best position for every sail and adjust them accordingly when rigging. Writing down all the settings for every single sail somewhere is a good idea /my memory is pathetic and I look at my notes every time before rigging just in case/. I seem to like 28" length now-a bit longer for downwind or when using seat harness /which I dont use anymore/. Spreading them a fist lenght appart is good enough for bigger sails.
Perhaps the best check point of your rig trim and mast compatibility is the luff side end of the batten just above the boom. At max setting it is supposed to be behind the mast just touching it and at min setting it would be overlapping the mast a bit ending at the center line and not protruding past it. Leaner trimes sail is better for early planing then bagged out one-counterintuitively it seems.
There is a light wind setting in this instructions aswell, but I dont like it and prefer the medium setting for light wind instead.