I assume it was a hazard to navigation where it sank or the owner was otherwise legally required to get the boat out of there. Otherwise, I can't imagine why a salvor (who is entitled to a percentage of the value of a boat they rescue) would voluntarily spend all that time and money to raise a boat worth about $5000. Likewise, if it was the owner behind the rescue, he would have to pay a towing company/salvor way more in fees than the boat was worth.