Deballasting of Fore peak tank, which was full, was commenced. The suction pressure was positive until the sounding was 2.0 m and the gland packing was found leaking. Below 2.0m sounding the suction went into slight vacuum and the leakage of gland stopped. Deballasting was normal until the tank sounding was 150 cm when the pump started showing positive pressure. The most probable cause leading to pump losing suction could be:lost suction& the suction pressure gauge first started fluctuating and the suddenly