If you do try scraping it yourself make sure you protect your back. Scraping a boat in cramped quarters like under your cradle can cause very serious back damage. I scraped my 22ft boat last year and ended up in hospital for 6 weeks and had a further 8 weeks of therapy. I had herniated 2 discs in my back. I had only spent 5 hours working under the boat - total time. Really screwed up my sailing. Make sure you scape for no more than one hour at a time. Leave and stretch for at least 1/2 hour.