I booked some owner time a while ago through Sailonline for an upcoming trip. In addition to some initial due diligence, I asked the owner if I could call the charter company to confirm that they are in fact the owner. That provided a little bit of comfort knowing they were selling me time on a boat that they at least owned. I have also kept tabs on the boat making sure their ad hasn't disappeared from Sailonline in addition to checking the reservation system making sure the boat is still blocked out those days for me. Still, you never know until you are on the boat. I have saved all of the e-mail and other correspondence just in case anything goes wrong. I guess the steep discount you receive is partially in exchange for the small risk you take booking directly through the owner.