Wind load on the boat
API · /anchor-api
Boat Anchoring API
healthy
4,461 Subscribers
Boat-anchoring maths as an API, computed locally and deterministically — the scope, swing and load numbers a sailor or boater sets the hook by. The scope endpoint gives the rode to let out: scope = rode ÷ the vertical from the seabed to the bow roller (water depth + bow height), measured at high tide, so anchoring in 20 feet with a 4-foot bow at the classic 7:1 means paying out 168 feet of rode — let out more in a blow, and never less than 5:1 on all chain. The swing endpoint gives the circle the boat swings on: radius = the horizontal reach of the rode (√(rode² − vertical²)) plus the boat length, so that 168-foot rode on a 30-foot boat sweeps a 196-foot radius — the room you must leave every other boat, which swings too. The load endpoint gives the wind load the ground tackle has to hold, 0.00256 × drag coefficient × frontal windage area × wind speed², which quadruples every time the wind doubles — 50 square feet of windage takes 138 lb at 30 mph but 553 lb at 60. Everything is computed locally and deterministically, so it is instant and private. Ideal for sailing and boating apps, anchoring and cruising tools, ground-tackle sizing calculators, and seamanship study aids. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. Estimates — add current, waves and a safety margin.
api.oanor.com/anchor-api
API health
healthy- Uptime
- 100.00%
- Server probes · 24h
- Avg latency
- 77 ms
- Server probes · 24h
- Subscribers
- 4,461
- active
- Total calls
- 80
- last 7 days
Pricing
Pick a tier — billed monthly, cancel anytime.
Free
Free
- 520 calls / month
- 2 requests / second
- Hard cap (429 above quota, no overage)
- 520 calls/month
- 2 req/sec
- Scope + swing + wind load
- No credit card
Starter
€5.05 /month
- 13,800 calls / month
- 6 requests / second
- Hard cap (429 above quota, no overage)
- 13,800 calls/month
- 6 req/sec
- Swing circle & load
- Email support
Pro
€16.50 /month
- 86,000 calls / month
- 15 requests / second
- Hard cap (429 above quota, no overage)
- 86,000 calls/month
- 15 req/sec
- Cruising-app pipelines
- Priority support
Mega
€49.20 /month
- 270,000 calls / month
- 36 requests / second
- Hard cap (429 above quota, no overage)
- 270,000 calls/month
- 36 req/sec
- Platform scale
- Dedicated SLA
Built by
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api.oanor.com/stellarasset-api
Set and Drift API
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api.oanor.com/setanddrift-api
Boat Propeller API
Boat-propeller maths as an API, computed locally and deterministically — the slip, RPM and pitch numbers that decide whether a boat hits its numbers or labours. The slip endpoint gives propeller slip from the pitch, the prop RPM and the actual boat speed: theoretical speed = pitch × prop RPM ÷ 1215, and slip = (theoretical − actual) ÷ theoretical — a 19-inch prop at 2000 RPM should make 31 knots in theory, so a real 26.6 knots is about 15 % slip, normal for a clean planing boat. The prop-rpm endpoint gives the propeller RPM from the engine RPM and the gear (reduction) ratio — a 2:1 gearbox spins the prop at half engine speed — and, with a pitch, the theoretical no-slip speed at that RPM. The pitch endpoint gives the pitch needed to reach a target speed at a prop RPM and expected slip, pitch = target × 1215 ÷ (prop RPM × (1 − slip)), so you can prop the boat to let the engine reach the top of its wide-open-throttle range instead of lugging. Everything is computed locally and deterministically, so it is instant and private. Ideal for boating and marine apps, repower and prop-shop tools, performance calculators, and seamanship study aids. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. Estimates — hull, load and bottom condition shift real slip.
api.oanor.com/propeller-api
Sailing & Hull Design API
Sailing and naval-architecture maths as an API, computed locally and deterministically — the hull-speed and design-ratio numbers a sailor, boat-shopper or yacht designer sizes a boat with. The hullspeed endpoint gives the theoretical displacement speed limit from the waterline: hull speed = 1.34 × √LWL (feet) in knots, so a 25-foot waterline tops out around 6.7 knots (7.7 mph, 12.4 km/h) — with a tunable coefficient up to about 1.5 for light, easily-driven hulls, since planing boats leave the formula behind entirely. The ratios endpoint computes the two classic performance numbers: the Sail Area/Displacement ratio, SA/D = sail area ÷ (displaced volume in ft³)^⅔ using displaced volume = displacement ÷ 64 lb/ft³ for seawater — around 16–18 is a typical cruiser and 20-plus is sporty — and the Displacement/Length ratio, DLR = (displacement in long tons) ÷ (0.01 × LWL)³, where under 200 is light and over 300 is heavy, each returned with a class label. The ballast endpoint gives the ballast ratio = ballast ÷ displacement × 100, a rough proxy for stiffness and sail-carrying power that most cruisers hit near 35–45 %. Everything is computed locally and deterministically, so it is instant and private. Ideal for sailing, boating, marine, yacht-brokerage and boat-design app developers, boat-comparison and rig-sizing tools, and naval-architecture calculators. Pure local computation — no key, no third-party service, instant. Imperial units. Live, nothing stored. 3 compute endpoints. Design-ratio estimates, not a velocity prediction program.
api.oanor.com/sailing-api
Frequently asked questions
Quick answers about pricing, quotas, and integration.
How do I get an API key for Boat Anchoring API?
Sign up for free at oanor.com, generate an API key from the developer dashboard, and call Boat Anchoring API with the x-oanor-key header. No credit card needed for the free tier.
What's the rate limit for Boat Anchoring API?
Free tier allows 1 request per second. Paid plans scale up to 50 requests per second on the Mega tier. Hard limits return HTTP 429 above the quota — no surprise overage charges.
How much does Boat Anchoring API cost?
Boat Anchoring API has a free tier with 100 calls / month. Paid plans start at €5.05 / month with higher quotas and faster rate limits.
Can I cancel my subscription anytime?
Yes. Plans are billed monthly and you can cancel anytime from your billing dashboard. No long-term contracts and no cancellation fee.
Is Boat Anchoring API GDPR-compliant?
All requests to Boat Anchoring API go through our EU-based gateway. Your upstream API key never leaves our server and no personal data is shared with the upstream provider beyond the request you send.
Pick an endpoint from the list on the left to see its details and try it.
Code snippets
Sign up to get an API key, then call any path under your slug.
curl https://api.oanor.com/anchor-api/SOME_PATH \
-H "x-oanor-key: oanor_test_..."const res = await fetch("https://api.oanor.com/anchor-api/SOME_PATH", {
headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();$ch = curl_init("https://api.oanor.com/anchor-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);import requests
r = requests.get(
"https://api.oanor.com/anchor-api/SOME_PATH",
headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())Ratings
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