373 FZUS51 KBOX 092304 CWFBOX Coastal Waters Forecast for Massachusetts and Rhode Island National Weather Service Boston/Norton MA 704 PM EDT Sat Aug 9 2025 Coastal waters from the Merrimack River MA to Watch Hill RI out to 25 NM ANZ200-101200- 704 PM EDT Sat Aug 9 2025 .Synopsis for Massachusetts and Rhode Island coastal waters... High Pressure is continuing to bring pleasant boating conditions through midweek. Winds gradually increase form the SW Tue and Wed but remain below small craft criteria. $$ ANZ250-101200- Coastal waters east of Ipswich Bay and the Stellwagen Bank National Marine Sanctuary- 704 PM EDT Sat Aug 9 2025 .TONIGHT...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and SE 1 foot at 8 seconds. .SUN...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SE 3 ft at 9 seconds. .SUN NIGHT...S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SE 3 ft at 8 seconds and S 2 ft at 3 seconds. .MON...S winds 10 to 15 kt. Seas 3 to 4 ft. Wave Detail: E 4 ft at 9 seconds and SW 2 ft at 3 seconds. .MON NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to 4 ft. Wave Detail: E 3 ft at 9 seconds and S 2 ft at 4 seconds. .TUE AND TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 3 to 4 ft. Wave Detail: S 3 ft at 4 seconds and E 3 ft at 9 seconds. .WED THROUGH THU NIGHT...NW winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to 3 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ251-101200- Massachusetts Bay and Ipswich Bay- 704 PM EDT Sat Aug 9 2025 .TONIGHT...S winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and SE 1 foot at 8 seconds. .SUN...S winds 5 to 10 kt, becoming SE 10 to 15 kt in the afternoon. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and S 1 foot at 3 seconds. .SUN NIGHT...S winds 10 to 15 kt, becoming SW 5 to 10 kt after midnight. Seas 2 to 3 ft. Wave Detail: SE 3 ft at 8 seconds and S 1 foot at 3 seconds. .MON...SW winds 5 to 10 kt, becoming S 10 to 15 kt in the afternoon. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and S 1 foot at 3 seconds. .MON NIGHT...SW winds 10 to 15 kt. Gusts up to 20 kt in the evening. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and S 2 ft at 4 seconds. .TUE AND TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and S 2 ft at 3 seconds. .WED THROUGH THU NIGHT...N winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ231-101200- Cape Cod Bay- 704 PM EDT Sat Aug 9 2025 .TONIGHT...SE winds 5 to 10 kt, becoming S after midnight. Seas around 2 ft. Wave Detail: E 2 ft at 4 seconds and SE 1 foot at 8 seconds. .SUN...S winds 5 to 10 kt. Seas around 2 ft. Wave Detail: E 2 ft at 8 seconds and S 1 foot at 2 seconds. .SUN NIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: E 2 ft at 8 seconds and S 1 foot at 2 seconds. .MON...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: E 2 ft at 9 seconds and SW 1 foot at 2 seconds. .MON NIGHT THROUGH TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas around 2 ft. Wave Detail: E 2 ft at 9 seconds and SW 1 foot at 3 seconds. .WED THROUGH THU NIGHT...W winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 3 seconds and E 1 foot at 8 seconds. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ254-101200- Coastal waters from Provincetown MA to Chatham MA to Nantucket MA out 20 nm- 704 PM EDT Sat Aug 9 2025 .TONIGHT...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and SE 1 foot at 8 seconds. Patchy fog after midnight with vsby 1 NM or less. .SUN...SE winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 8 seconds and SE 1 foot at 8 seconds. Patchy fog in the afternoon with vsby 1 NM or less. .SUN NIGHT...SW winds 5 to 10 kt. Seas 2 to 4 ft. Wave Detail: SE 4 ft at 8 seconds and SW 1 foot at 3 seconds. Patchy fog. Vsby 1 NM or less. .MON...SW winds 5 to 10 kt. Seas 3 to 4 ft. Wave Detail: E 4 ft at 9 seconds. Patchy fog in the morning with vsby 1 to 3 NM. .MON NIGHT THROUGH TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft. Wave Detail: E 4 ft at 9 seconds and SW 2 ft at 3 seconds. .WED THROUGH THU NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 3 ft at 4 seconds and E 2 ft at 8 seconds. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ255-101200- Coastal Waters extending out to 25 nm South of Marthas Vineyard and Nantucket- 704 PM EDT Sat Aug 9 2025 .TONIGHT...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and SE 2 ft at 7 seconds. Patchy fog after midnight with vsby 1 to 3 NM. .SUN...NE winds around 5 kt, becoming S in the afternoon. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and SE 2 ft at 8 seconds. Patchy fog in the afternoon with vsby 1 NM or less. .SUN NIGHT...SW winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SE 3 ft at 8 seconds and SW 1 foot at 4 seconds. Patchy fog. Vsby 1 NM or less. .MON...SW winds 5 to 10 kt. Seas 2 to 4 ft. Wave Detail: E 4 ft at 9 seconds and W 2 ft at 3 seconds. Patchy fog in the morning with vsby 1 to 3 NM. .MON NIGHT THROUGH TUE NIGHT...SW winds 10 to 15 kt. Seas 2 to 4 ft. Wave Detail: E 3 ft at 9 seconds and W 2 ft at 4 seconds. .WED THROUGH THU NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 3 ft at 5 seconds and E 2 ft at 8 seconds. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ256-101200- Coastal Waters from Montauk NY to Marthas Vineyard extending out to 20 nm South of Block Island- 704 PM EDT Sat Aug 9 2025 .TONIGHT...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and SE 2 ft at 8 seconds. .SUN...SW winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and SE 2 ft at 7 seconds. .SUN NIGHT...SW winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SE 3 ft at 7 seconds and SW 1 foot at 3 seconds. Patchy fog. Vsby 1 NM or less. .MON...SW winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 3 ft at 9 seconds and SW 2 ft at 3 seconds. Patchy fog in the morning with vsby 1 NM or less. .MON NIGHT THROUGH TUE NIGHT...SW winds 10 to 15 kt. Seas 3 to 4 ft. Wave Detail: E 3 ft at 9 seconds and SW 2 ft at 4 seconds. .WED THROUGH THU NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 3 ft at 5 seconds and E 2 ft at 8 seconds. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ232-101200- Nantucket Sound- 704 PM EDT Sat Aug 9 2025 .TONIGHT...E winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE 2 ft at 7 seconds. .SUN...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: S 1 foot at 3 seconds and SE 1 foot at 7 seconds. .SUN NIGHT...SW winds around 10 kt. Seas around 2 ft. Wave Detail: E 2 ft at 8 seconds and SW 1 foot at 2 seconds. Patchy fog. Vsby 1 to 3 NM, decreasing to 1 NM or less after midnight. .MON...SW winds 10 to 15 kt. Seas around 2 ft. Wave Detail: SW 2 ft at 3 seconds and E 2 ft at 9 seconds. Patchy fog in the morning with vsby 1 NM or less. .MON NIGHT THROUGH TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas around 2 ft. Wave Detail: SW 2 ft at 3 seconds and E 2 ft at 9 seconds. .WED THROUGH THU NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 3 seconds and E 1 foot at 8 seconds. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ233-101200- Vineyard Sound- 704 PM EDT Sat Aug 9 2025 .TONIGHT...SE winds 5 to 10 kt, becoming SW after midnight. Seas around 2 ft. Wave Detail: SE 1 foot at 6 seconds. .SUN...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SW 1 foot at 2 seconds and SE 1 foot at 7 seconds. .SUN NIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: E 2 ft at 8 seconds and SW 1 foot at 3 seconds. Patchy fog. Vsby 1 to 3 NM, decreasing to 1 NM or less after midnight. .MON...SW winds 5 to 10 kt, increasing to 10 to 15 kt in the afternoon. Seas around 2 ft. Wave Detail: SW 2 ft at 3 seconds and E 2 ft at 8 seconds. Patchy fog in the morning with vsby 1 to 3 NM. .MON NIGHT THROUGH TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas around 2 ft. Wave Detail: SW 2 ft at 4 seconds and E 2 ft at 9 seconds. .WED THROUGH THU NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and E 1 foot at 8 seconds. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ234-101200- Buzzards Bay- 704 PM EDT Sat Aug 9 2025 .TONIGHT...SE winds 5 to 10 kt, becoming SW after midnight. Seas 1 foot or less. Wave Detail: E 1 foot at 4 seconds and SE 1 foot at 7 seconds. .SUN...SW winds around 5 kt, increasing to around 10 kt in the afternoon. Seas 1 foot or less, then around 2 ft in the afternoon. Wave Detail: SE 1 foot at 7 seconds and E 1 foot at 9 seconds, becoming SW 1 foot at 2 seconds and SE 1 foot at 7 seconds. .SUN NIGHT...SW winds 5 to 10 kt. Seas 1 foot or less. Wave Detail: SW 1 foot at 3 seconds and SE 1 foot at 7 seconds. Patchy fog. Vsby 1 NM or less. .MON...SW winds 5 to 10 kt, increasing to 10 to 15 kt with gusts up to 20 kt in the afternoon. Seas 1 foot or less, then around 2 ft in the afternoon. Wave Detail: SW 1 foot at 3 seconds and SE 1 foot at 8 seconds, becoming SW 2 ft at 3 seconds and E 2 ft at 9 seconds. Patchy fog in the morning with vsby 1 NM or less. .MON NIGHT THROUGH TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas around 2 ft. Wave Detail: SW 2 ft at 4 seconds and E 2 ft at 9 seconds. .WED THROUGH THU NIGHT...W winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and E 1 foot at 8 seconds. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ235-101200- Rhode Island Sound- 704 PM EDT Sat Aug 9 2025 .TONIGHT...SE winds 5 to 10 kt, becoming SW after midnight. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and E 1 foot at 8 seconds. .SUN...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and S 1 foot at 3 seconds. .SUN NIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE 2 ft at 7 seconds and SW 1 foot at 3 seconds. Patchy fog. Vsby 1 NM or less. .MON...SW winds 5 to 10 kt, increasing to 10 to 15 kt in the afternoon. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 3 seconds and SE 2 ft at 9 seconds. Patchy fog in the morning with vsby 1 NM or less. .MON NIGHT THROUGH TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 4 seconds and SE 2 ft at 9 seconds. .WED THROUGH THU NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 3 ft at 5 seconds and E 1 foot at 8 seconds. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ237-101200- Block Island Sound- 704 PM EDT Sat Aug 9 2025 .TONIGHT...SE winds around 5 kt, becoming SW around 5 kt after midnight. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and E 2 ft at 9 seconds. .SUN...SW winds around 5 kt, becoming S in the afternoon. Seas around 2 ft. Wave Detail: SE 2 ft at 8 seconds and S 1 foot at 2 seconds. .SUN NIGHT...SW winds 5 to 10 kt. Seas around 2 ft. Wave Detail: SE 2 ft at 7 seconds and SW 1 foot at 3 seconds. Patchy fog after midnight with vsby 1 to 3 NM. .MON...SW winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 3 seconds and E 2 ft at 8 seconds. Patchy fog in the morning with vsby 1 NM or less. .MON NIGHT THROUGH TUE NIGHT...SW winds 10 to 15 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 3 seconds and E 2 ft at 9 seconds. .WED THROUGH THU NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Wave Detail: SW 2 ft at 5 seconds and SE 1 foot at 9 seconds. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ230-101200- Boston Harbor- 704 PM EDT Sat Aug 9 2025 .TONIGHT...SE winds 5 to 10 kt, becoming S after midnight. Waves 1 foot or less. .SUN...S winds around 5 kt, becoming SE in the afternoon. Waves 1 foot or less, then around 2 ft in the afternoon. .SUN NIGHT...SW winds 5 to 10 kt. Waves around 2 ft in the evening, then 1 foot or less. .MON...SW winds 5 to 10 kt, becoming S in the afternoon. Waves 1 foot or less, then around 2 ft in the afternoon. .MON NIGHT...SW winds 5 to 10 kt. Waves around 2 ft in the evening, then 1 foot or less. .TUE AND TUE NIGHT...SW winds 10 to 15 kt. Waves around 2 ft. .WED THROUGH THU NIGHT...N winds 10 to 15 kt with gusts up to 20 kt. Waves around 2 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ ANZ236-101200- Narragansett Bay- 704 PM EDT Sat Aug 9 2025 .TONIGHT...S winds 5 to 10 kt, becoming SW after midnight. Waves around 2 ft. .SUN...SW winds around 5 kt, becoming S in the afternoon. Waves 1 foot or less, then around 2 ft in the afternoon. .SUN NIGHT...SW winds 5 to 10 kt. Waves around 2 ft in the evening, then 1 foot or less. Patchy fog after midnight with vsby 1 NM or less. .MON...SW winds 5 to 10 kt. Gusts up to 20 kt in the afternoon. Waves around 2 ft. Patchy fog in the morning with vsby 1 NM or less. .MON NIGHT THROUGH TUE NIGHT...SW winds 10 to 15 kt with gusts up to 20 kt. Waves around 2 ft. .WED THROUGH THU NIGHT...W winds 10 to 15 kt with gusts up to 20 kt. Waves 2 to 3 ft. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height. $$ For the latest updates...please visit our webpage at www.weather.gov/boston You can follow us on Facebook at www.facebook.com/NWSBoston You can follow us on Twitter at @NWSBoston