Broken Ground-Horseshoe Shoal, between tidal current predictions

Now

Flood 0.5 ktToward ESE (107°)

Next slack

Mon 12:01 AMEDT

Next max flood

1.1 kt9:24 PM

Next max ebb

1.0 ktMon 2:49 AM

Knots along the channel: above the line the flood, running in toward ESE (107°); below it the ebb, running out toward W (276°). Times are Eastern Daylight Time. Today: ebb 1.0 kt 2:11 AM, slack 5:43 AM, flood 1.1 kt 9:08 AM, slack 11:44 AM, ebb 1.0 kt 2:31 PM, slack 6:02 PM, flood 1.1 kt 9:24 PM.

• Small Craft Advisory Small Craft Advisory issued September 27 at 3:09PM EDT until September 28 at 8:00AM EDT by NWS Boston/Norton MAUntil Mon 8:00 AM
  Full text

  * WHAT...East winds 10 to 20 kt with gusts up to 25 kt and seas 4 to 6 feet. * WHERE...Nantucket Sound. * WHEN...Until 8 AM EDT Monday. * IMPACTS...Conditions will be hazardous to small craft.

  Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in hazardous conditions.

The flood is the tidal current running in from the sea, the ebb the current running back out. Slack water is the short turn between them, when the current is weakest: the time to cross a strong channel, anchor, or dive. Slack in a channel is not the time of high or low tide; it can come hours after.

Speeds are knots along the channel's main axis, and directions are degrees true toward which the water flows, as NOAA prints its tables. A current against the wind stands the waves up steep and close together.

Predictions are astronomical: the moon and the sun, not the weather. Strong wind, river flow after heavy rain and storm surge all change the real current. This is a subordinate station: NOAA predicts it from a nearby harmonic station by fixed corrections to the times and speeds of its slack waters and maxima, so the curve between them is less exact.

• Point Gammon, 1.2 miles south ofSubordinate current station3.0 mi
• Lewis Bay entrance channelSubordinate current station5.7 mi
• Halfmoon Shoal, 1.9 miles northeast ofSubordinate current station6.6 mi
• Monomoy Point, 6 miles west ofSubordinate current station7.0 mi
• Cross Rip ChannelSubordinate current station7.0 mi
• Wreck Shoal-Eldridge Shoal, betweenSubordinate current station7.5 mi
• Cotuit Bay entrance (Bluff Point)Subordinate current station8.6 mi
• Cape Poge Lt., 3.2 miles northeast ofSubordinate current station8.7 mi

• Tide times at Hyannis Port 5.7 mi
• Tide times at Cotuit Highlands 8.8 mi
• Tide times at South Yarmouth, Bass River 9.5 mi
• Forecast for Hyannis, MA
• Open the live map with tidal currents
• All tidal current stations in Massachusetts

Tidal current predictions from NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS), station ACT1736, bin 1: original at NOAA. Marine alerts from the National Weather Service.