103. Your vessel has run aground and upon taking fuel oil tank soundings, you find that a fuel tank level has increased. You therefore should suspect __________.

A rising fuel tank level after grounding likely indicates seawater entering through a hull crack. Grounding can damage the hull, allowing seawater to enter tanks, especially those against the hull plating. Seawater is denser than fuel, so its ingress raises the measured tank level. This sudden increase points to external water entry, not condensation, fuel quality issues, or flushing system contamination.