Rethinking Hydrography

Our Company
Unabara is a vertically integrated manufacturer of game-changing tools for shallow water hydrography and oceanography. Combining our competencies in underwater acoustics and piezo-ceramics with ASIC and MEMS semiconductor technology, we are changing how surveyors obtain and process data.

Our Name
Our corporate name, Unabara, has its origin in the 8th century Japanese word which denotes the ocean, the sea, the deep, the abyss.

Our Products
Our HydroBar Sound Velocimeter & Bar Check Tool is an easy to use instrument for rapidly and most accurately performing bar check calibration of echo sounders and obtaining sound velocity profiles. Please visit for full details.

Our HydroBook single-beam hydrographic echo sounder offers such features as sub-centimeter depth resolution, 0.10 meter (4 inch) minimum depth of operation, and user-selectable frequency & transducer beamwidths. View these and other features never before available in a shallow water hydrographic echo sounder at

Our Hydro-2F Multi-Frequency Synthetic Beam Bathymetric & Sea Floor Sonar provides a high frequency (200 Khz. nominal) channel for sea bottom determination and charting of bathymetry; and a second lower frequency for bottom penetration; the user may select 10, 12, 18, 24, 28 or 30 Khz. for the lower channel. Uses for the low frequency channel include hydrographic surveys in high turbidity waters, determination of true hard sea bottom to determine navigable depth, detection of back-filled bridge pile scour holes, etc.. For more information, please visit the MULTI-FREQUENCY web presentation at (U.S. & all other countries, except Japan) (Japan only; Japanese & English)

Unabara, HydroBar & HydroBook are registered trademarks of Unabara Corporation; all rights reserved 2012
Rethinking Hydrography is a registered service mark of Unabara Corporation 2012