This helps greatly. Unless you would advise I'll use her this season (4 months remaining) then put her inline to be inspected. The last bottom painting was 2009 and remains largely in great shape. But this will give me the nudge to lift her condition.The cracks have all the appearance of the common keel to keel stub joint crack. Affectionately know as [insert boat brand] smile.
Keels are usually set into the stump with a generous layer of a bedding compound (often 5200) and then some fairing compound around the joint. Over time the fairing compound fails due to the different expansion rates of iron and fiberglass and is not a structural issue. However, the only way to be certain that this is the problem is to haul the boat, inspect the joint, and re-torque the keel bolts.
Without seeing the crack up close and personal, I really can't give you any advise on the safety of sailing the boat this summer. The photos seem to suggest the crack is benign, however, it could also be the result of a grounding or there could be additional damage.Unless you would advise I'll use her this season (4 months remaining) then put her inline to be inspected.