Meanwhile, lagoon water rushing back into the space vacated by the rising gas bubble started a tsunami-like water wave which lifted the ships as it passed under them. At 11 seconds after detonation, the first wave was 1,000 feet (305 m) from surface zero and 94 feet (29 m) high.[68] By the time it reached the Bikini Island beach, 3.5 miles (6 km) away, it was a nine-wave set with shore breakers up to 15 feet (5 m) high, which tossed landing craft onto the beach and filled them with sand.[69]