I passed Mt Martha a while ago and wondered what it would be like for windsurfing. Any good? Best spot? Best winds? Any reefs or rocks to avoid?

NE = close to cross shore with plenty of swell
N = Cross on with plenty of swell

To the right hand side there is a reef close to shore, if you gain height it will be in your gybe zone. Getting too much height will put you in towards the cliffs where the wind will be fickle.

The shore break can get nasty as it's one of those beaches that goes deep as you step off the shore. Always funny when it's someone else getting hammered though.

Can be some pebbles & small rocks in shore break area.

Probably the best bay spot on a NE for waves

Yep agree on all those wind directions. It's usually my local spot of choice if I feel like being a social windsurfer. On a decent wsw, especially on a weekend you will get 10+ sailors there.

Here is some more info.
thewindmap.com/wiki/index.php/Mt_Martha-Australia_%26_New_Zealand

hmmm.... *strokes chin*....