Open Waters MCP server

• Registry nameio.openwaters/aisverified in the MCP registry

The registry name sits under openwaters.io. The registry only lets a publisher use that namespace after proving control of the domain through DNS or HTTP.

• Stateanswerschecked 2026-10-20
• Tools6
• Server calls itselfaiscast
• Server version0.17.0
• Protocol version2025-06-18

On 2026-10-20 the server answered initialize and tools/list without a sign-in. First answer in 525 ms.

• Its tools do track live vessel traffic within a chosen area, but not look up tide predictions for stations worldwide; view depth contours and seamarks on nautical charts.
• Checked on 2 of the 7 days it takes to judge reliability.

Said by rules from the measurements above. The likely first call is a model's pick from the tool list; read its description before relying on it.

• INITE MCP scoreafter a weeka score needs 7 daily checks: 2 so far
• What an agent can do with it1 of 3 use cases
• Use7 GitHub stars
• Answeredmeasuring2 of the 7 daily checks it takes to print a share
• Median first answer543 ms
• Space in an agent's context≈ 2,195 tokensthe definitions of all its tools (6), which an agent carries on every turn
• Tool definitionsA · 97 of 100
• Typed results6 of 6 toolsdeclared outputSchema: results come typed, read once

• Parameters without a description: in 1 of 6

A program checks the server once a day: initialize and tools/list, no model. Tokens are the definitions' length at about four characters a token. The grade averages six checks of every tool's name, description, schema and annotations; it says how well the tools are described, not whether they work. The score weighs what was measured and nothing else: answering (30%), doing the product's job (25%), definitions (20%), context (10%) and use (15%). A part that was not measured is left out, and a hidden instruction caps the score at 40. The state of vendors' MCP servers: method and numbers →

• find_vessels_in_area

  Vessels currently inside a latitude/longitude bounding box, newest report first, with optional kind and ship-type filters. Use for what is in a port, a strait, or a stretch of coast. Anonymous calls may cover 100 square degrees per call.

• find_vessels_near

  Vessels within a radius (default 10 NM, maximum 50) of a point or of another vessel's last known position, nearest first, each with distance and bearing from the centre. Use for what is near this position or what is around vessel X.

• get_coverage

  Where Open Waters AIS is hearing AIS right now: sources with their current delay, stations, freshness, and vessel counts. Pass a bounding box to learn which stations cover it and how many vessels are in it, or a station id for that…

• get_vessel_track

  The positions heard from one vessel over a time range, oldest first, with speed, course, and navigational status. Positions implying an impossible speed for the vessel are left out. Use for where a ship was yesterday, when it left port…

• get_vessels

  Last known position and particulars of specific vessels by MMSI (Maritime Mobile Service Identity), or by IMO number with a feeder or partner token: the last report heard for each, however long ago, with destination, ETA, draught, and…

• search_vessels_by_name

  Vessels whose name contains the text, case-insensitive, among every vessel the network has heard, each with its last known position. Use to turn a name into an MMSI, then get_vessels or find_vessels_near for detail. An optional bounding…