Beach and boat
Boat ramp planner: when can I launch and get back?
Enter the tide height your ramp needs and see every window above it, so the launch and the return both work.
Myrtle Beach, SC: water above 2.7 ft
6 windows
47 h 24 min in all over 7 days, daylight only
How windows are computed · Not for navigation
Wednesday, October 14. The dashed line is your level; shaded hours are night.
Published by Radif Partners · How the tides are computed · predictions downloaded October 13, 2026
At a tidal ramp the question is not when high tide is, but how long the water stays deep enough to float the boat off the trailer, and whether it will still be there when you come back. This planner lists, for any of the 92 stations on the site, every window when the predicted water stays above the height you set, over 3 to 60 days, in daylight or not, and draws the day's curve with that level across it. The calculator in the text below helps you find the height: your boat's draft on the trailer, plus a safety margin, minus the depth already at the end of the ramp at 0 ft. Heights are in feet above Mean Lower Low Water, the zero of NOAA charts and tide tables.
Finding the height your ramp needs
Most ramps have a usable depth that depends on their slope and on how much sand or mud has built up at the end. The simplest way to learn it is once, at a known tide: note the predicted height when you launched comfortably, or when the trailer wheels went off the end of the concrete. The calculator below turns a draft and a depth into a minimum tide height.
Lowest tide that still floats your boat off the ramp
Launch when the tide is at least
2.0 ft
| Draft plus margin | 3.0 ft |
| Depth already there at 0 ft | 1.0 ft |
Enter the result in the boat-ramp planner to see the hours that work. Not for navigation.
Plan the return, not just the launch
A morning launch on a falling tide can leave the ramp too shallow by the time you return. Read the end of the window, not the start, and plan to be back with time to spare. On coasts with big ranges, such as Tybee Island or Portland, the water drops more than a foot an hour in the middle of the ebb; on the Gulf the change is slow but the wind can hold water out for a day after a cold front.
Reading the window list
Each line of the list is one stretch of time with the water above your level: its date, start, end, length and the highest water inside it. On a semidiurnal coast you usually get two windows a day, one around each high; on a diurnal Gulf coast often one long one. If the list is empty, the level is too high for the period: lower it, accept night windows, or look further ahead to the days around the new and full moon, when the highs are highest. Click a line to draw that day's curve under the list.
Inlets and current
Depth at the ramp is one question; the current in the channel or inlet beyond it is another. Ebb against an onshore swell makes inlets rough, and many boaters prefer to run them on the flood. The planner gives heights, not currents, and nothing here is for navigation: local knowledge, charts and marine forecasts come first.