Steve,

Yes you are right in your assumption - I took two full turns out of the diamonds to reduce the pre-bend, as a result the bend in the mast is fairly even, but also remember that unlike an alu mast, a carbon mast is built with specific bend characteristics. A tapered carbon mast (as I have) even more so.

Without diamonds the bare mast is softer twothirds of the way between the spreaders and hounds. It appears to be slightly more flexible in the topmast as well. This seems to give a straightish section from base to just above the spreaders, then a gentle curve through the hounds to a top that flexes and flicks off in the gusts.

The unloaded prebend though (major axis) is an even curve along the length of the luff groove. When the mast is loaded and rotated the tapered section is able to bend to weather and back freeing the leech 'automatically'.

As to disturbed airflow - the flow at the leech is fine as demonstrated by the streamers. From recollection my centre (in terms of fore/aft) tell tales were flying correctly but I believe that the front tell tales in the upper third were lifting occasionally to signify an updraft every so often. A lot of the time though they were flying correctly.

As we were the fastest thing out there (and that includes the rescue boats) and two Dart 18's capsized and retired and a Nacra F18 lost its mast (too little diamond tension), I wasn't going to worry too much about a little turbulence at times!