NGDC Hydrographic Surveys Data Exchange (HYD93) Reader/Writer

The Hydrographic Surveys Data Exchange Reader module provides FME with direct access to data in HYD93 format.


HYD93 is an exchange format for hydrographic survey data (bathymetry soundings and hydrographic features). While HYD93 data is shipped with four files, including a header file, an actual dataset is represented as a single data records file. A HYD93 dataset is either an ASCII HYD93 file or a Binary HYD93 file.

A data record consists of a variable number of lines or records. It represents a bathymetric sounding value or hydrographic feature value with corresponding position, value type, and cartographic code. The HYD93 Binary Format is a binary representation of the HYD93 data record.

Reader Overview

The HYD93 format consists of a single data record file.

Writer Overview

The HYD93 writer writes an ASCII-encoded header file, and all attributes of a feature to an ASCII or binary data record file.