Beginner, would be about 5-10 knots, but if you work the progression, you won't be beginner for long.

Unless you are very gifted (and there are people I know who are and have fast tracked beginnner/intermittent phases), you'll struggle learning to windsurf on small gear in 20+ knots.

with the right gear you can, especially if you're young fit, determined and not worried about making a fool of yourself.
If the above is you, I'd recommend learning the hard fast way, on a board about 15litres more than your weight in Kg, and depending on your weight a sail between 4.0 and 6.0 square metres.
This method bypasses the learn to uphaul in light winds with a smallish sail on a big board.
You start by learning sail control on the beach, sail in board, standing alongside it, practise hanging your weight on the boom, hang on to rig with front hand, control power with your back. When you can automatically balance your weight with sail power, you're ready to learn to beach start then water start.
This process will involve a lot of crashes, but once you have sail control skills you're away.

I'd recommend getting somebody who knows what to do to help, a lot of the stages are counter intuitive, it's easy to try the impossible if you don't have clear guidance.

If you think the above is not for you, learning to uphaul is a bit harder in 20kts if you can find some really flat water that will help.
A wide floaty board will give stability possibly up to double your Kg weight in litres, and a smaller sail than previously recommended.

whatsausername said..

5 to 10 knots.. Those numbers I could work with also.

I didn't realize you guys could get out in such light winds.

5/10 kts for very first uphaul lesson, only the lightest sailors on huge gear can plan in these wind speeds.
Unless you can hire/borrow suitable big stuff you'll have a board not very suitable for 20knts.

And it's a big jump from 5 to 10 to 20, the intermediate stages are hard to miss out using the uphaul method.
So how young/old, fit are you? Are you up for a challenge?

Go to a school, take a lesson and take it from there. After a few sessions, you might be able to short circuit the beginner phase, and go to intermediate gear.

Decrepit: with a bit of help from swell/chop, I can normally plane in 10 knots (but not at the moment, as I'm so out of practice due to not sailing enough over winter ).

whatsausername said..

Hmm I suppose I can do two wind sports.. Just don't tell my friends

What should I be looking at spending on a first rig?

Hmmm, how long is a piece of string?

There are a few alternatives, you can get old gear for almost nothing, but old gear isn't as easy to learn on, especially if you're going the uphaul method.

You don't say where you live, but here in Aus you can get fairly good 5 year old, second hand stuff reasonably cheap.
There are pitfalls though, some sails are mast specific, if you get the combo wrong, it could make things harder for you.

There was also a period about 5 years ago when some manufactures gave "equivalent volumes". When boards started to get wider, they planned easier, so to give the new buyer a sense of how easy their new board planned compared to their old board, the volume was over stated. This of course gives people who are interested in floatation the wrong information, what should just float you will sink.

clarence said...

Learning in 20 plus knots would put most people off.

Clarence

You know those big starboard start boards? The ones that have the orange 3m sails on them, that you look at and think to yourself "there's no way that things gonna plane"? When I was getting started I took one out in about 25knts, it started planing, I shat myself.

Needless to say, that was when I decided to go buy some gear to call my own.

I think you are going down the right path. Talk to the experts, trying to learn on inappropriate gear is going to be difficult, possible but difficult. Also, talk to other windsurfers, they are really quite friendly despite what you may think by some comments on the forum. We always welcome new riders but be warned, it is not an easy sport to learn but the rewards are well and truly worth it.
One good thing about windsurfers, at least the larger ones, you can always slog home if the wind drops.