I'm taking this from the other thread so not to hijack it.
)
What I meant was: don't try a sinky full-on speed board, you'll flounder.
When you're going really really deep off the wind you don't have much force on the sail, so you need a bit more width or volume to keep going. Something I learnt after my first two LOCs where I kept dropping off the plane.
This year I used a 94 iSonic (15 litres bigger than before), which although it slowly sinks when there's absolutely no wind, was perfect for me and the conditions.
It all depends on your skill level as well. At 100 kgs I'd consider something around the 110 - 120 litre mark, but remember that you need a bit of nose kick up (otherwise known as rocker) so that negotiating the waves at the end is a bit easier.
The best advice is to do a test run a couple of weeks before the event, or even some ocean sailing deep off the wind so you can make sure that you are in the right ballpark with your setup. I know what works for me, but you might have a whole different way of sailing that works for you.
Good luck 
Thanks Neb,
Although I would really like to do the LOC one day, I'm really not planning to do it next year. I need to do some serious ocean sailing before I even think about it.
From your response : it slowly sinks when there's absolutely no wind.
It seems that my 135L Bombora may work temporarily, before I step further down to a board capable of doing LOC.
Obelix, I think the bombora would be a backward step.
Maybe have a go at hiring a few boards from one of the schools .
Although you are 100kg in stronger winds something around the 135L mark should be a good progression. Ideally not a race board. A starboard carve for example. How much are you looking to spend?
Here is an example but perhaps a bit big. www.seabreeze.com.au/Classifieds/Windsurfing/Boards/~rn866/2006-Starboard-Carve-145-145-litres.aspx?search=8x7uhC3xupKjU3ZsLRWHW%2buEIxdjFxoU
There is a 133L version too.
Obelix, I'm similar size to you...currently around 107kg.
I recently acquired a 135 Crossfire for light wind sailing, so I'm unloading my 120L Kinetic Centurion.
Board is a few seasons old (I think it's a 2006 model), but it's in reasonable condition and I don't want a lot for it ($400 with bag and I can probably chuck in some fins).
You are welcome to demo this board. Give me a shout next time you're sailing at Pinnaroo and I can bring it down for you to try. It is a race board, but I've used it at Pinnaroo and it handles the chop OK. I used it in this year's LOC, and apart from being a bit overpowered it was OK as it has a reasonable amount of rocker.
this is turning into a Pinna(roo)s thread...
Pointman's offer sounds too good to refuse Obelix, go for it!
after a 15 year absence from sailing i picked up a 118 JP super sport. At the time i was about 105 kg. It only took about 1 session to get the balance right to uphaul on it and pretty much started water starting staight away.
The really nice thing about a board about 120 lt is its big enuf to float you yet small enuf that once you improve you will keep on using it for a long time.
Within 12 months on it i can carve gybe about 70% and have leanred to tack it as well (altho need to do this fast to avoid sinking the nose.)
I have clocked 30 knots on it.
I find its easy to tune it to different conditions using different fins . in light winds and 7.5 sails ill put on a stock 44" fin which gives it a lot of lift. in heavy conditions with 6 m sails i put smaller 32 or 36 " fin which reduces the lift a lot and lets you handle a rougher conditions without the tail walking.
Going from 160 down to 135 wont give you much of a perfomance boost and you will grow out of that size pretty fast. droping down to 120 will give ya a better top end range and better performance. It will be a slightly harder learning curve but well worth it in the long run.
If you sail regularly you will prob also shed a few KGs, im down to 95 kg (from 105) from only windsurfing in the last 12 months and the 120 now feels super floaty.
Craig
Your response is encouraging. Thanks for that 
