I suspect you have a bigger problem here than just the crack which is serious. The opening will have allowed water to infiltrate the balsa core. You really need to get ahold of a moisture meter to understand the extent of the problem throughout the hull. The blisters alone tell me you likely have wet balsa below the waterline and that is unfortunately somewhat common in these boats.
This is all repairable, if you know how to mix a drink, if you did paper mache' in kindergarten and you can occasionally read some directions you can do this work yourself. If you have to pay for the work to be done that will be a tough one to sort out. You will need a few tools and some serious elbow grease. The guys on this site have been supervising me pretty successfully on a similar big project.
Your first tool to buy is the moisture meter. You need it for this boat and every other boat you might ever want to buy.
