What this pair does. Together, Home Station and Offset at Home customize JaxTides to your specific fishing spot. Home Station picks the closest NOAA gauge; Offset at Home applies a small time correction so the gauge's predictions match the water at your actual dock or launch. Set both once, and the Current Tide hero, the tide schedule, and your launch-window timeline all show times tuned to where you fish.
Home Station — which gauge to read from. NE Florida options run from Fernandina Beach in the north to Matanzas Inlet in the south, plus St. Johns River and ICW gauges in between (Sisters Creek, Mayport Bar Pilots Dock, Mayport Jetties, Downtown Jacksonville, Buckman Bridge, Black Creek, Shands Bridge, Palm Valley, Tolomato River, Vilano, Anastasia Island). Pick the one nearest your dock, ramp, or favorite spot. Some stations are continuous hourly (NOAA publishes a full hourly tide curve); others are tagged (hi/lo), where NOAA only publishes the high/low events and JaxTides interpolates the rest of the curve — see the (hi/lo) FAQ entry below.
Offset at Home — a small time correction. Adjustable in 5-minute increments. Positive (+) pushes the listed times later; negative (−) pulls them earlier. Default is ±0 min. The offset only affects tide times for your home station — switching the main picker to a different station shows that station's raw NOAA predictions with no offset applied. The offset never changes tide heights, only the times.
Why offsets are needed. NOAA gauges sit at fixed locations — a pier, a bridge piling, a channel marker. Your dock or launch is almost certainly somewhere else: up a creek, around a bend, behind a marsh. The same tide event reaches your spot a few minutes earlier or later than the gauge. The offset reconciles the two so the times you see in JaxTides are accurate for where you actually fish.
How to calibrate (step by step).
- In JaxTides, check the listed time of the next low tide for your home station.
- Go to your dock, ramp, or fishing spot at low tide and watch the water carefully.
- Look for dead low — the moment the water pauses, then starts to rise. This is "slack low water." It's a window of roughly 5–10 minutes; with a little practice you can pin it down.
- Note the actual clock time you observed slack.
- Open Settings, find the Offset at Home stepper, and nudge it (one click = 5 minutes) until JaxTides' listed low-tide time matches what you saw. Use + if your spot's tide is later than the gauge; − if earlier.
- Set once and you're done — the same offset applies to every future tide event for your home station.
Why dead low and not dead high? Mathematically, either slack works — both are well-defined reference moments. But dead low is the better target in practice for two reasons:
1. Visibility. At dead low, exposed structure (oyster bars, dock pilings, marsh banks, mud flats) gives you fixed visual references to see the water stop receding. At dead high the water covers most of those references — much harder to pin the exact moment.
2. Use-case alignment. The decisions that bite — "can I float over this bar?", "is the ramp deep enough?", "is the flood pushing yet?" — happen at and around dead low. Calibrating where it matters most is the right call.
Caveat for tidal creeks. In shallow channels (parts of the ICW and St. Johns tributaries), flood and ebb don't propagate at the same speed, so the offset measured at dead low may differ by a few minutes from one measured at dead high. Calibrating at dead low gives you accurate dead-low timing — exactly what launch decisions hinge on. If you want high-tide timing equally accurate, observe a dead high too and check whether your low-water offset still aligns; if not, decide which side matters more for your fishing and calibrate there.
Conditions that can throw the calibration off temporarily.
- Strong sustained wind. Onshore wind pushes water in (delaying lows, raising and slowing highs); offshore wind does the opposite. After a few days of unusual wind, your calibration may temporarily look "wrong" — wait for normal conditions before adjusting the offset.
- Atmospheric pressure. Low pressure raises water levels and can subtly shift slack timing; high pressure does the reverse. Effects are small but real.
- Heavy rainfall / river flow. Spots in the St. Johns or its tributaries see freshwater inflow disrupt tide timing after major rain events. The fix is patience, not a new offset.
- Spring vs neap tides. Spring tides (around full and new moons) have larger ranges; neap tides (around quarter moons) have smaller. The offset is approximately stable across these, but for an extreme location you may want to verify your calibration during both.
Re-calibrating. You shouldn't need to re-calibrate often — the physics doesn't change. But if you notice JaxTides times drifting from observation by more than 5–10 minutes consistently across normal weather, re-check on a calm day. The offset is stored locally in your browser, so it persists between visits unless you clear site data or use a different device.
Scope summary. Home Station = which gauge. Offset at Home = how many minutes to shift that gauge's predictions for your spot. Together they make every future tide time you see in JaxTides accurate for your specific fishing location.
