I have a boat that has set outside for the past 9 months without a cover. The mildue on the seats is pretty bad. I've tried over the counter mildue cleaner but I can't get the seats clean. There are still black mildue spots all over the seats and steering wheel. Is there anything I can do short of going to a vinyl repair shop?

If it really sat 9 months, they might be too far gone. Sun and weather is really hard, even for marine vinyl. You could try a spray bottle of bleach and water and see if it would help, but I'm betting they need to be recovered.

Have you tried powerwashing them?

I haven't tried power washing. I'll do that. Thanks.

Mothers Leather & Vinyl Cleaner is about the best stuff I've found. I had grease on my seats from riding in the back of my truck and it took the stuff right off.

Scotch Brit pads and comet my do the trick.