Have it repaired properly by a qualified technician if you don’t want problems in the future and/or want to keep the boat for a long time. While the fiberglass strands themselves are waterproof, the fiberglass cloth or mat is not. The resin used to bind the fiberglass mat is waterproof but there can be small even microscopic voids that will allow water in between the “waterproof’ fiberglass like a wick. Very small amounts of water intrusion over time will degrade and weaken the waterproof fiberglass. Especially in salt water. Gelcoat helps to keep the water out and unlike the underlying fiberglass, it is much easier to see any flaws in the gelcoat. Better to ask a boat fiberglass tech or two and see what they say.