Grand Lake St Marys Seaplane Base Seaplane Base
O12 · St Marys, OH · Non-towered
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Weather
METAR observed
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TAF forecast
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Sun & FAA night2026-08-07 · night begins 09:16 PM
| Event | Local (EDT) | UTC |
|---|---|---|
| Morning civil twilight Loggable night ends | 06:10 AM | 10:10Z |
| Sunrise | 06:40 AM | 10:40Z |
| Sunset | 08:46 PM | 00:46Z |
| Evening civil twilight Loggable night begins | 09:16 PM | 01:16Z |
Plan a flight from O12
Winds aloft NOAA forecast · 3,000 to 53,000 ft
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Full reports: nearest reporting station
Advisories
Airspace hazards
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Runways
Headings shown are true (magnetic variation unavailable).
| Runway | Length | Your margin |
|---|---|---|
| 09/27 | 7,000 ft |
Prefer one flat page? Full runway details for O12 → · New to pattern entries? The 45° entry, explained → · Teaching here? Print the O12 kneeboard →
Comms & NavAids
Communication frequencies
Taxi & takeoff
Source: FAA NASR (current 28-day cycle).
Nearby navigation aids
ROD 117.50 · DQN 114.50
| NavAid | Type | Freq · ch | Range | Radial / Dist magnetic |
|---|---|---|---|---|
| ROD · Rosewood | VORTAC | 117.50 · 122X | High | r312° / 25.5 NM |
| DQN · Dayton | VOR/DME | 114.50 · 92X | Low | r353° / 31.8 NM |
Prefer one flat list? All O12 frequencies →
Charts & procedures
Airport info
Airport information
- FAA LID
- O12
- Coordinates
- 40.5410, -84.4907
- Elevation
- 871 ft MSL
- Sectional chart
- DETROIT
- Airport use
- Public
- Control tower
- No
- ARTCC
- INDIANAPOLIS (ZID)
- Flight service (FSS)
- DAYTON · 122.1R · 1-800-WX-BRIEF
- NOTAM facility
- DAY
- Attendance
- APR-NOV ALL 0800-1700
- Segmented circle
- No
- Activated
- 1995/04
- Distance from city
- 5 W
Night operations
- Pilot-controlled lighting
- Usually keyed on CTAF 122.9 — confirm the click sequence in the Chart Supplement ↗
FAA night windows (civil twilight, loggable night §1.1, currency §61.57) are under Sun & FAA night in the Weather section.
Services fuel · repairs · oxygen · attendance
- Fuel available
- 100LL
Ownership & management 2 contacts
Remarks FAA · 6 notes
General
- NO NGT OPS.
- NO PUB DOCKS; PPR FOR PVT DOCK TIE UP; CALL KOZY MARINA 419-394-8797.
- FOR CD CTC COLUMBUS APCH AT 614-338-8537.
Fuel
- 100LL AVBL ON REQ, PPR, CTC KOZY MARINA 419-394-8797.
Contact
- CELL 419-656-7060.
Attendance
- ARPT CLSD NOV 15 TO APR 1 & MEMORIAL & LABOR DAY.
Nearby airports
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Also nearby: OA11 Heitman Field (15 NM) · OH91 Dave Rice Ultralightport (private) (15 NM) · OH51 Kathamel Airport (private) (15 NM) · 3OH6 Youngpeter Airport (private) (16 NM)
About O12
Grand Lake St Marys Seaplane Base (O12) is a seaplane base in St Marys, OH, at 871 ft MSL. It has 1 runway, the longest 7,000 ft, with no control tower (pilot-controlled). This page shows live METAR/TAF weather, runway crosswinds, frequencies, navaids, and FAA charts for O12, refreshed from the Aviation Weather Center and FAA NASR.
Does O12 have a control tower?
No. Grand Lake St Marys Seaplane Base is a non-towered (pilot-controlled) seaplane base; use the published CTAF/UNICOM in the Comms & NavAids section.
What is the longest runway at O12?
Grand Lake St Marys Seaplane Base has 1 runway; the longest is 7,000 ft. See the Runways section for headings, surface, and lighting.
Where is O12?
Grand Lake St Marys Seaplane Base is in St Marys, OH, at an elevation of 871 ft MSL. Coordinates: 40.5410, -84.4907.
Fly out of O12 often?
Save O12 as your home base in the SkyReady app for a one-tap Go/No-Go readiness brief, weather alerts, and automatic FAA currency — free to log.
Weather is live from the Aviation Weather Center; airport facility data is from the FAA NASR (28-day cycle). For planning and education only; always verify against official sources. Open O12 in a full tool: METAR/TAF decoder, crosswind calculator, sun & night times, or the density altitude calculator. Planning from here? Find the nearest airport with fuel or an approach, or check whether an IFR alternate is required.