this was more operator error. I haven't been in winds like this before so I had some lessons.
1. Don't run dead downwind with spinnaker, full main, following seas and gusts to 35! You cant depower boat. I should of reached and stuck pole more forward to hide spin behind main. Good plan- You need to work on your crew work and set-up a little. As a gust starts: release vang, pole forward, spin sheet out, dump main. The crew needs to do this quickly.
2. I should of had the main up and jibb down to have a more stable boat. Not necessarily. A 120% jib on the roller furler would have been a better option and then start reefing main as wind builds. You will need that headsail to power through waves/chop.
3. More caution when gybing. Chicking gybe instead perhaps. That's a tough one, Chicken gybes with a spinnaker??? With a jib we usually have a crew carefully pull the mainsheet over while another crew rapidly pulls sheet in and then releases sheet as it passes center line. Practice helps with this and it is not a maneuver inexperienced crew should try.
4. Should of had backup handheld vhf
I couldn't afford it if I broke stuff this offten. Granted the travelor was 25 years old and the main sheet was equally old. I haven't broken something that we have replaced yet like the winch's or blocks.
A Garhauer traveler is a nice replacement. Garhuaer rigid vang is nice to have. With both vang sheeting the main is a possibility for upwind work in high winds. You vang the main hard and lower traveler so that only back third of main is working. Crew plays traveler up and down in the puffs. Try ebay for replacement main sheet. You can usually find 8 or 10MM VPC cut end for around $1.00/ft or less.
We get lots of stuff of Craigslist and second wind
