130 tidal inlets analyzed from Maine to Texas. 41% have zero professional survey coverage — including some of the most dangerous passages on the coast.
Eric Whyne · Data Machines · February 13, 2026
📄 Download PDFEvery USACE district produces data differently. No standard delimiter, no standard naming, no standard API. To access depths, a consumer must navigate an 8-step gauntlet.
Comma, space, and tab — varying even within the same district.
State Plane zones from Maine to Texas, each with unique projections.
The actual depth data is <5% of the archive. The rest is GIS overhead.
Latin-1 and UTF-8 metadata files with no declared encoding.
This 8-step process requires GIS expertise, programming ability, and familiarity with each district's conventions. It is inaccessible to ordinary mariners.
A consumer must implement district-specific parsing logic for virtually every aspect of the data format.
The inlets most likely to lack survey coverage are the natural, unjettied inlets — precisely where conditions are most dangerous and depth data would save the most lives.
Many of the most dangerous inlets on the coast have zero professional depth data
Currents exceeding 10 knots. Unmarked channel. No USACE survey.
Shallow bar breaks across entire entrance. Most dangerous in FL. No survey.
Controlling depth of just 6 inches. One of the most dangerous in the US.
100% success rate across all 12 districts, all 77 surveyed inlets. Automated, real-time, accessible to any mariner.
Building a system that handles all 12 districts required solving dozens of edge cases — but as the Pelagic Insight system demonstrates, it is achievable. The technology exists today. The barrier is data infrastructure, not capability.
The current model waits for someone to die before issuing warnings. A data-driven proactive model publishes survey data within hours and flags dangerous shoaling automatically.