The Sea-Bird Electronics SBE 26 SEAGAUGE is a wave level and tide recorder with a pressure sensor, accurate clock, precision thermometer and optional SBE 4M conductivity sensor. Pressure data are integrated to give sea level or are burst recorded at rates up to 4 Hz to characterize waves. The standard pressure sensor is a 20 meter (45 psia) Quartzonix, with a temperature-compensated quartz element. Optionally, the SBE 26 can be configured with a Paroscientific Digiquartz pressure sensor with a temperature-compensated quartz element in 13 ranges, from 1 to 6800 meters (15 to 10,000 psia). more information from Sea-Bird Electronics