Castle island tidal current predictions

Now

Flood 0.2 ktToward NW (304°)

Next slack

Sat 12:18 AMEDT

Next max flood

0.4 ktSat 9:23 AM

Next max ebb

0.3 ktSat 3:04 AM

Knots along the channel: above the line the flood, running in toward NW (304°); below it the ebb, running out toward SE (128°). Times are Eastern Daylight Time. Today: ebb 0.3 kt 2:45 AM, slack 4:48 AM, flood 0.4 kt 8:52 AM, slack 12:07 PM, ebb 0.4 kt 3:23 PM, slack 5:42 PM, flood 0.4 kt 9:15 PM.

• Storm Warning Storm Warning issued September 25 at 2:58PM EDT until September 26 at 8:00PM EDT by NWS Boston/Norton MAUntil Sat 8:00 PM
  Full text

  * WHAT...Northeast winds 20 to 25 kt with gusts up to 50 kt and waves around 3 feet. * WHERE...In Massachusetts coastal waters, Boston Harbor. In Rhode Island coastal waters, Narragansett Bay. * WHEN...Until 8 PM EDT Saturday. * IMPACTS...Storm force winds and hazardous waves will capsize or damage vessels and reduce visibility.

  Mariners should remain in port, alter course, and/or secure the vessel for severe conditions.

• Measured, along the channel
• Predicted

A NOAA PORTS current meter, bin 17. Wind, river flow and storm surge push the real current off the prediction; the meter measures the difference.

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.

• Fort Independence, 0.1nm north ofHarmonic current station0.2 mi
• Fort Independence, 0.3 nmi east ofSubordinate current station0.5 mi
• Boston Channel Light No.5Harmonic current station0.7 mi
• Thompson Island, 0.7 nmi NNE ofSubordinate current station0.9 mi
• Ted William TunnelHarmonic current station1.0 mi
• South Boston, Pier 4, 0.2 nmi NNE ofSubordinate current station1.2 mi
• Spectacle Island, 0.4nm north ofHarmonic current station1.4 mi
• City Point, 0.8 nmi SSE ofSubordinate current station1.4 mi

• Tide times at Boston 2.1 mi
• Tide times at Moon Head 2.5 mi
• Tide times at Deer Island (south end) 2.7 mi
• Forecast for Boston Seaport, MA
• Open the live map with tidal currents
• All tidal current stations in Massachusetts

Tidal current predictions and real-time current measurements (PORTS) from NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS), station bh0101, bin 17: original at NOAA. Marine alerts from the National Weather Service.