Sea Surveyor, Inc
SINCE 1985



Precision marine surveys for the engineering community



Amazon River Survey

Client: Bechtel Corporation

Completion Date: 1999

Contract Value: $1.5 Million

Sea Surveyor conducted the first survey of the previously uncharted Ucayali and Urubamba Rivers in the Amazon Region of Peru. The purpose for the survey was to map 400-miles of natural river channels and prepare Navigation Charts that would allow tugs and barges to reach the natural gas fields discovered in the eastern Andes Mountains.

Sea Surveyor designed a 35′ survey boat and supervised its construction in a Peruvian shipyard. After accepting delivery of the survey boat, one of our surveyors helmed the boat upriver over 1,000 miles to reach the survey area. Our surveyor lived aboard the survey boat for 3-months while accomplishing the following tasks:

• Installed 8 water level recorders on the river bottom at 50-mile intervals that continuously monitored the river rise and fall,

• Established the first permanent benchmarks in the Peruvian Amazon and determined their elevations using advanced GPS techniques over a 1,200-mile baseline,

• Completed a detailed hydrographic survey of 400-miles of the Ucayali and Urubamba Rivers, and identified the location and depth of the natural deep channels,

• Prepared the first series of navigation charts for upper Amazon tributaries with soundings referenced to a common River Datum.

Using a satellite telephone, the survey data was transmitted from the Peruvian Amazon to Sea Surveyor’s U.S. office, where the navigation charts were prepared daily. Sea Surveyor used the bathymetric charts to design a navigation channel that allowed tugs to avoid shoals by following the natural river channel.


Amazon GPS           Amazon Survey Boat

Mapping the River with Fast-Static GPS                                  Amazon River Survey Boat


Overlapping river navigation charts (left), Chart 9 of 20 (top right), and close-up showing that centerline soundings match cross-sectional soundings at their intersections (bottom right).