Ched, Tac and I hosted a debrief session on Saturday after racing at Charleston Race Week. I took some notes of what we talked about. Here they are:-  

Viper 640 designer and honorary Class Governor Brian Bennett has just published a new Tuning Guide for the Viper 640.  The document includes a discussion of the Viper 640's critical rig controls,  fundamentals of setting up the Viper 640 rig for best performance, and quick reference tables for both rig tune and sail trim settings appropriate to different wind strengths.  Those rig tune and sail trim tables are suitable for lamination to carry with you on your boat as a quick reference tool.

We encourage all Viper sailors to download and read this guide, and put its recommendations into practice when setting up your boat.

It is impossible to quantify the value of having the designer of the Viper 640 so involved with the class.  Thank you, Brian, for this fantastic resource!

Download:
V640_bennett_tuning_guide_rev1_1.dpf  updated April 11, 2009.

See the last page of the Tuning Guide for a Revision History detailing changes/updates to each version.

Lifting the keel is easy on the Viper. There is a spectra line rigged from a tang on the port side spreader base, just hook up the 4:1 keel lift purchase.

Standard Keel Lift using 4:1 purchase                                                         The view from below

Here are some photos of the very crew-friendly standard console layout for the Viper ...

Standard Console

Tack and Halyard 

To rig your spinnaker, first attach the tack to the tack line that comes out of the pole. Then attach the head to the spinnaker halyard and hoist a few feet. If you have a shackle on the halyard, tape it to prevent inadvertent release.

Sheet 

Then attach the spinnaker sheet. The mid point of the spinnaker sheet is attached to the clew, leaving the two ends to run out to the spinnaker blocks on either side of the boat. We recommend attaching a small pennant to the mid point of your spinnaker sheet (a small piece of line spliced through the sheet). Tie this to the spinnaker clew with a small bowline and tape the knot.  Eye splicing a small spectra pennant through the sheet ensures it doesn't snag on the head stay during jibes and douses. It is also faster and easier when rigging and de-rigging because you can leave the spinsheets in place. 

The alternative is a simple loop knot using the spinnaker sheet through the clew as shown (but note the size of the knot and you have to take the sheet all the way out of the blocks to untie the clew).