1.   Decades of data collected from the ground, using tide gauges placed along the coasts, have generally shown that ocean levels are rising.

2.   Nevertheless, these observations corroborate the trend of sea level measurements made over the last century using tide gauges.

3.   Over the last century, tide gauges indicated an average sea-level rise of four-hundredths to eight-hundredths of an inch a year.

4.   Scientists rely on tide gauges, which can account only for changes close to shore.

5.   DIAP is performing daily hydropgrahic surveys using a heave compensator, tide gauges set up at nearby locations and receivers on the survey vessel and all dredgers.