Where is the garboard strake located?

The garboard strake is specifically located on both sides of the keel of a vessel. It is the first plank of the hull that is laid next to the keel and runs parallel to it, forming a critical part of the ship's structure. This area is essential as it helps to provide the necessary strength to the hull and plays a vital role in preventing water from entering the vessel.

The other options do not accurately describe the position of the garboard strake. The waterline refers to the level of the water's surface when the ship is in water but does not indicate where the garboard strake is. The bow is the front part of the ship, while the stern refers to the rear; neither of these positions represents where the garboard strake is situated relative to the keel. Therefore, the correct answer emphasizes the garboard strake's role and location alongside the keel.