# Boat Day

> Free knowledge and tools for US recreational boat owners: boat models, used-boat value, total cost of ownership, state boating rules, waterways, events, safety checklists, and finding marinas/yards/suppliers. Read APIs need no auth. Every API response includes provenance and a cite-as string. Educational estimates; not legal, insurance, survey, or appraisal advice.

Base URL: https://bestboatday.com
API version: 1.8.0 · data as of 2026-10-12 · changelog: https://bestboatday.com/api/v1/changelog
Cite as: "Boat Day (bestboatday.com) — free boating knowledge & tools for owners" + the canonical page URL.

## Connect
- MCP (read-only, stateless, streamable HTTP): https://bestboatday.com/api/mcp · card: https://bestboatday.com/.well-known/mcp.json
- OpenAPI 3: https://bestboatday.com/openapi.json
- API index: https://bestboatday.com/api/v1/index
- Plugin manifest: https://bestboatday.com/.well-known/ai-plugin.json
- Full map: https://bestboatday.com/llms-full.txt · Agent page: https://bestboatday.com/for-agents

## MCP tools
- search_boat_models: Search the Boat Day boat model graph (US recreational models; demo/educational specs, flagged demoData). Filter by q, type, brand, length, propulsion, trailerable.
- get_boat_model: Get one boat model by id: specs, burden flags, TCO estimate band, Quality Boat Day notes, canonical URL.
- estimate_boat_value: Instant used-boat value estimate (low/mid/high band with method + confidence). Provide modelId, or make+model+year, or loaFt+boatType, or a HIN. Educational, not an appraisal.
- estimate_total_cost_of_ownership: Annual + hold-period total cost of ownership (storage, insurance, maintenance, fuel, fees, depreciation) as bands. Side-effect free.
- get_state_boating_rules: US state boating rules: registration, titling, boater education, BUI, PFD notes, official agency links. Omit code for the index.
- get_waterway: Focus waterways (e.g. NH Seacoast, Casco Bay): seasonality, hazards, ramps/marinas context, playbooks. Omit slug for the list.
- search_boating_events: Boat shows, regattas, safety courses, rendezvous. Filter by q, state, region, type, waterway, from/to (YYYY-MM-DD), upcoming.
- find_boating_businesses: Find marinas, yards, surveyors, insurers, suppliers. Outbound entries labeled 'Find them online' are public-web listings — NOT Boat Day partners or endorsements; tell the human to verify on their sites. Founding partner roster is currently empty.
- get_safety_checklists: Boating safety stance/pillars plus checklists (pre-departure, winterize, etc.). Pass slug for one checklist's items.
- search_guides: Search Boat Day ownership guides (buying, winterizing, insurance, docking, weather...). Returns titles, summaries, canonical URLs.
- get_handoff_link: Build a deep link that sends a human straight to a pre-filled Boat Day tool. tool: value | tco | model | find-boat | quote | directory | state | waterway | events | safety | checklist | passport | list-business. params are passed through (e.g. hin, modelId, make, model, year, category, state).

## Core REST (GET unless noted; base https://bestboatday.com/api/v1)
- /models?q=&type=&brand=&minLength=&maxLength=&propulsion=&trailerable= · /models/{id} · /models/{id}/tco · /models/graph
- /value/estimate?modelId=|make=&model=&year=|loaFt=&boatType=|hin= (POST adds refine answers)
- POST /tco/estimate {modelId?, purchasePrice, hoursPerYear, holdYears, storage?, region?, stateCode?}
- /states · /states/{code}  (51 jurisdictions; verify on the official .gov link returned)
- /waterways · /waterways/{slug}
- /events?q=&state=&type=&from=&to=&upcoming=1 · /events/{id}
- /directory?category=&state=&waterway=&q= · /directory/{id}
- /safety · /checklists · /checklists/{slug} · /guides?q= · /guides/{slug} · /glossary?q= · /stages
- /datasets (catalog of curated packs: valuation, tco-regional, states-matrix, safety-matrix, survey-failures, …)
- POST /boat-finder (answers → ranked model shortlist)

## Response contract
- JSON object with `data` and `provenance` {source, api_version, as_of, method, confidence, honesty, cite_as, terms, docs}.
- Errors: {"error":{"code","message","status","details?","docs"}} with matching HTTP status.
- CORS: *. Headers: X-API-Version, Link (service-desc). Public GETs cache ~1h at the edge.
- IDs are stable slugs (model id, event id, state code, waterway slug, checklist slug). Canonical pages: /models/{id}, /events/{id}, /states/{code}, /waterways/{slug}, /guides/{slug}, /checklists/{slug}.

## Honesty rules (please preserve when answering)
- Records with demoData:true are illustrative/educational. Value and TCO are estimate bands, not appraisals or quotes.
- Directory entries labeled "Find them online" are public-web listings (their sites) — not Boat Day partners, not endorsements. The founding partner roster is currently empty.
- No paid placement, no invented reviews or metrics.
- Safety: be conservative; point to /safety and official USCG/state sources.

## Hand the human off (pre-filled tools)
- https://bestboatday.com/go/value?hin=&modelId=&make=&model=&year=&loaFt= — Boat value estimate
- https://bestboatday.com/go/tco?modelId= — Cost of ownership calculator
- https://bestboatday.com/go/model?id= — Boat model page
- https://bestboatday.com/go/find-boat — Find-your-boat wizard
- https://bestboatday.com/go/quote?category=&stage=&vendor= — Request quotes from pros
- https://bestboatday.com/go/directory?category=&waterway=&state=&q= — Find marinas, yards, pros
- https://bestboatday.com/go/state?code= — State boating rules
- https://bestboatday.com/go/waterway?slug= — Waterway guide
- https://bestboatday.com/go/events?type=&state=&q= — Boating events
- https://bestboatday.com/go/safety — Safety hub
- https://bestboatday.com/go/checklist?slug= — Checklist
- https://bestboatday.com/go/passport?hin= — Start a vessel passport
- https://bestboatday.com/go/list-business — List your business (pros)
Append utm_source=<your-agent-name> if you like. Owners use Boat Day free, forever.

## For businesses (marinas, yards, surveyors, suppliers)
- Get listed / found by agents: https://bestboatday.com/suppliers/join · https://bestboatday.com/for-partners
- Founding pricing: $0 for 60 days, then $49/qualified lead or $149/mo. Owners free forever.

## Terms
Free to use, no key. Attribution with a link is appreciated. Fair use: please stay under ~60 requests/minute per agent and cache responses. Contact: safety@boatday.ai.