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# Sail Forecast
- URL: https://dangraf.io/work/sail-forecast/
- Published: 2026-10-09T14:12:08.000Z
- Updated: 2026-10-09T14:20:42.000Z
- Description: A rolling 14-day view of which days are actually worth going sailing, with tide-safe passage plans.
- Author: Dan Graf
- Tags: Marine, #work, #Import 2026-10-09 15:24

Generic weather apps tell you the wind speed. They don't tell you whether Saturday is a good day to take your boat out of a tidal harbour and back. Sail Forecast does.

![A day rated Good: hourly wind, waves, current and tide, coloured against my own limits, with the hatched windows where there isn't enough water to get out](https://dangraf.io/content/images/2026/10/sailforecast-day.jpg)

A day rated Good: hourly wind, waves, current and tide, coloured against my own limits, with the hatched windows where there isn't enough water to get out

## What it does

- Twice a day it pulls weather, marine and tide forecasts for a configurable home port.
- It scores each of the next 14 days against hard safety limits, then adds a qualitative rating on top.
- On demand, it plans tide-safe out-and-back sails and passages to named destinations.
- It records every run and highlights what changed since the last forecast.
- A mobile-first dashboard, with the port, boat, preferences and destinations all editable at runtime.

![The point of it all](https://dangraf.io/content/images/2026/10/ensign-at-sea-1.jpg)

The point of it all

## How it's built

A single Go service on an AWS Lightsail container service, backed by managed Postgres and deployed automatically on every push to `main`. It reuses the infrastructure of my AIS ship-tracking project to keep running costs close to zero.