601
FZUS51 KBOX 181104
CWFBOX

Coastal Waters Forecast for Massachusetts and Rhode Island
National Weather Service Boston/Norton MA
703 AM EDT Mon Aug 18 2025

Coastal waters from the Merrimack River MA to Watch Hill RI out
to 25 NM

ANZ200-190000-
703 AM EDT Mon Aug 18 2025

.Synopsis for Massachusetts and Rhode Island coastal waters...
High pres over Quebec gradually shifts east into the Maritimes this
week. All mariners are urged to closely follow the National
Hurricane Center Forecasts for the impacts of Major Hurricane
Erin...especially those with interests in the Atlantic. Although the
Major Hurricane will be passing well to the east of our waters later
this week...high seas are expected to enter our open waters from
large southerly swell.

$$

ANZ250-190000-
Coastal waters east of Ipswich Bay and the Stellwagen Bank
National Marine Sanctuary-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH THIS EVENING...

.TODAY...NE winds 15 to 20 kt with gusts up to 30 kt. Seas 5 to
7 ft. Wave Detail: NE 6 ft at 7 seconds and SE 1 foot at
13 seconds.
.TONIGHT...NE winds 5 to 10 kt. Gusts up to 20 kt in the evening.
Seas 3 to 5 ft. Wave Detail: NE 5 ft at 7 seconds and SE 2 ft at
12 seconds.
.TUE...E winds 5 to 10 kt. Seas around 3 ft. Wave Detail: NE 3 ft
at 7 seconds and SE 2 ft at 12 seconds.
.TUE NIGHT...SE winds 5 to 10 kt. Seas 3 to 4 ft. Wave Detail: E
2 ft at 7 seconds and SE 2 ft at 12 seconds.
.WED AND WED NIGHT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas 2 to 4 ft. Wave Detail: SE 3 ft at 14 seconds and E 2 ft at
8 seconds.
.THU...NE winds 10 to 15 kt with gusts up to 25 kt. Seas 4 to
6 ft. Wave Detail: E 4 ft at 5 seconds and SE 3 ft at 15 seconds.
.THU NIGHT...NE winds 20 to 25 kt with gusts up to 30 kt. Seas
5 to 8 ft.
.FRI...NE winds 20 to 25 kt with gusts up to 30 kt. Seas 6 to
9 ft.
.FRI NIGHT...SW winds 15 to 20 kt with gusts up to 25 kt. Seas
5 to 7 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.

$$

ANZ251-190000-
Massachusetts Bay and Ipswich Bay-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH THIS EVENING...

.TODAY...NE winds 15 to 20 kt, diminishing to 10 to 15 kt this
afternoon. Gusts up to 25 kt. Seas 3 to 5 ft. Wave Detail: NE
5 ft at 6 seconds and SE 1 foot at 13 seconds.
.TONIGHT...E winds 5 to 10 kt with gusts up to 20 kt, becoming NE
after midnight. Seas 2 to 4 ft. Wave Detail: NE 4 ft at 7 seconds
and SE 1 foot at 13 seconds.
.TUE...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: NE 3 ft
at 7 seconds and SE 1 foot at 11 seconds.
.TUE NIGHT...SE winds 5 to 10 kt. Seas around 2 ft. Wave Detail:
E 2 ft at 7 seconds and SE 1 foot at 13 seconds.
.WED AND WED NIGHT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas around 2 ft. Wave Detail: SE 2 ft at 4 seconds and SE 2 ft
at 16 seconds.
.THU...NE winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to
4 ft. Wave Detail: SE 3 ft at 4 seconds and SE 2 ft at
18 seconds.
.THU NIGHT THROUGH FRI NIGHT...S winds 15 to 20 kt with gusts up
to 30 kt. Seas 3 to 5 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.

$$

ANZ231-190000-
Cape Cod Bay-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 4 PM EDT THIS AFTERNOON...

.TODAY...NE winds 15 to 20 kt with gusts up to 30 kt. Seas 3 to
5 ft. Wave Detail: N 4 ft at 5 seconds and SE 1 foot at
13 seconds.
.TONIGHT...NE winds 5 to 10 kt. Gusts up to 20 kt in the evening.
Seas 2 to 4 ft. Wave Detail: N 3 ft at 6 seconds and SE 1 foot at
13 seconds.
.TUE...E winds 5 to 10 kt. Seas around 2 ft. Wave Detail: N 2 ft
at 5 seconds and SE 2 ft at 13 seconds.
.TUE NIGHT...SE winds 5 to 10 kt. Seas around 2 ft. Wave Detail:
SE 2 ft at 14 seconds and E 1 foot at 3 seconds.
.WED AND WED NIGHT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas around 2 ft. Wave Detail: S 2 ft at 15 seconds and SE 1 foot
at 4 seconds.
.THU...NE winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to
4 ft. Wave Detail: NE 3 ft at 3 seconds and S 3 ft at 17 seconds.
.THU NIGHT THROUGH FRI NIGHT...SW winds 20 to 25 kt with gusts up
to 30 kt. Seas 3 to 5 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.

$$

ANZ254-190000-
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA
out 20 nm-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH THURSDAY MORNING...

.TODAY...NE winds 20 to 25 kt, diminishing to 15 to 20 kt this
afternoon. Gusts up to 30 kt. Seas 5 to 7 ft. Wave Detail: NE
7 ft at 6 seconds and W 1 foot at 5 seconds.
.TONIGHT...NE winds 10 to 15 kt with gusts up to 25 kt. Seas 4 to
6 ft. Wave Detail: NE 6 ft at 7 seconds and SE 2 ft at
13 seconds.
.TUE...NE winds 10 to 15 kt with gusts up to 20 kt, becoming E
5 to 10 kt in the afternoon. Seas 3 to 5 ft. Wave Detail: NE 4 ft
at 8 seconds and S 3 ft at 14 seconds.
.TUE NIGHT...SE winds 5 to 10 kt. Seas 4 to 6 ft. Wave Detail: S
4 ft at 15 seconds and E 3 ft at 8 seconds.
.WED AND WED NIGHT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas 5 to 7 ft, except 8 to 11 ft S and E of Nantucket. Wave
Detail: S 7 ft at 17 seconds and E 2 ft at 8 seconds.
.THU...NE winds 15 to 20 kt with gusts up to 30 kt. Seas 8 to
11 ft, except 12 to 16 ft S and E of Nantucket. Wave Detail: S
10 ft at 17 seconds and E 4 ft at 5 seconds.
.THU NIGHT...NE winds 25 to 30 kt. Seas 9 to 13 ft.
.FRI...N winds 25 to 30 kt with gusts up to 35 kt. Seas 7 to
10 ft.
.FRI NIGHT...W winds 20 to 25 kt with gusts up to 30 kt. Seas
5 to 8 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.

$$

ANZ255-190000-
Coastal Waters extending out to 25 nm South of Marthas Vineyard
and Nantucket-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH THURSDAY MORNING...

.TODAY...NE winds 20 to 25 kt, diminishing to 15 to 20 kt this
afternoon. Gusts up to 30 kt. Seas 3 to 5 ft. Wave Detail: NE
5 ft at 5 seconds and SW 2 ft at 5 seconds.
.TONIGHT...NE winds 10 to 15 kt with gusts up to 25 kt. Seas 3 to
5 ft. Wave Detail: NE 5 ft at 7 seconds and SE 2 ft at
13 seconds.
.TUE...E winds 10 to 15 kt. Gusts up to 20 kt in the morning.
Seas 4 to 6 ft. Wave Detail: E 4 ft at 7 seconds and S 4 ft at
17 seconds.
.TUE NIGHT...E winds around 10 kt. Seas 5 to 8 ft. Wave Detail: S
6 ft at 15 seconds and E 3 ft at 8 seconds.
.WED...E winds 10 to 15 kt. Gusts up to 20 kt in the afternoon.
Seas 5 to 8 ft. Wave Detail: S 7 ft at 15 seconds and E 3 ft at
7 seconds.
.WED NIGHT...E winds 15 to 20 kt. Seas 6 to 9 ft, building to
8 to 11 ft after midnight. Wave Detail: S 8 ft at 16 seconds and
E 2 ft at 6 seconds, becoming S 9 ft at 16 seconds and E 1 foot
at 4 seconds.
.THU AND THU NIGHT...NE winds 20 to 25 kt, increasing to 25 to
30 kt. Seas 10 to 14 ft.
.FRI...N winds 25 to 30 kt with gusts up to 35 kt. Seas 7 to
10 ft.
.FRI NIGHT...S winds 20 to 25 kt with gusts up to 30 kt. Seas
5 to 7 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.

$$

ANZ256-190000-
Coastal Waters from Montauk NY to Marthas Vineyard extending out
to 20 nm South of Block Island-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH THURSDAY MORNING...

.TODAY...NE winds 20 to 25 kt, diminishing to 15 to 20 kt this
afternoon. Gusts up to 30 kt. Seas 3 to 5 ft. Wave Detail: NE
5 ft at 5 seconds and SW 2 ft at 5 seconds.
.TONIGHT...NE winds 10 to 15 kt with gusts up to 25 kt. Seas 4 to
5 ft. Wave Detail: N 4 ft at 5 seconds and SE 2 ft at 13 seconds.
.TUE...E winds 10 to 15 kt with gusts up to 20 kt. Seas 4 to
6 ft. Wave Detail: E 4 ft at 8 seconds and S 4 ft at 17 seconds.
.TUE NIGHT...E winds around 10 kt. Seas 6 to 8 ft. Wave Detail:
SE 6 ft at 16 seconds and E 3 ft at 7 seconds.
.WED...E winds 10 to 15 kt with gusts up to 20 kt. Seas 6 to
8 ft. Wave Detail: S 7 ft at 14 seconds and E 2 ft at 7 seconds.
.WED NIGHT...E winds 15 to 20 kt. Seas 7 to 10 ft. Wave Detail: S
9 ft at 16 seconds and E 1 foot at 5 seconds.
.THU...NE winds 20 to 25 kt with gusts up to 30 kt. Seas 10 to
14 ft.
.THU NIGHT...NE winds 25 to 30 kt with gusts up to 35 kt. Seas
11 to 15 ft.
.FRI...NE winds 25 to 30 kt with gusts up to 35 kt. Seas 8 to
11 ft.
.FRI NIGHT...S winds 20 to 25 kt with gusts up to 30 kt. Seas
5 to 8 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.

$$

ANZ232-190000-
Nantucket Sound-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 4 PM EDT THIS AFTERNOON...

.TODAY...NE winds 20 to 25 kt, diminishing to 15 to 20 kt this
afternoon. Gusts up to 30 kt. Seas 3 to 4 ft. Wave Detail: NE
3 ft at 4 seconds and W 1 foot at 5 seconds.
.TONIGHT...NE winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to
4 ft. Wave Detail: N 3 ft at 5 seconds and SE 1 foot at
13 seconds.
.TUE...E winds 5 to 10 kt. Gusts up to 20 kt in the morning. Seas
2 to 3 ft. Wave Detail: NE 2 ft at 6 seconds and S 2 ft at
16 seconds.
.TUE NIGHT...SE winds 5 to 10 kt. Seas 2 to 4 ft. Wave Detail: E
2 ft at 7 seconds and S 2 ft at 16 seconds.
.WED...E winds 10 to 15 kt. Seas 2 to 4 ft. Wave Detail: S 3 ft
at 15 seconds and E 2 ft at 7 seconds.
.WED NIGHT...E winds 10 to 15 kt. Gusts up to 20 kt after
midnight. Seas 4 to 6 ft. Wave Detail: S 3 ft at 16 seconds and E
2 ft at 4 seconds.
.THU AND THU NIGHT...NE winds 20 to 25 kt, increasing to 25 to
30 kt. Seas 5 to 7 ft.
.FRI...N winds 25 to 30 kt with gusts up to 35 kt. Seas 4 to
6 ft.
.FRI NIGHT...SW winds 20 to 25 kt with gusts up to 30 kt. Seas
3 to 5 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.

$$

ANZ233-190000-
Vineyard Sound-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 4 PM EDT THIS AFTERNOON...

.TODAY...NE winds 15 to 20 kt with gusts up to 30 kt. Seas 3 to
4 ft. Wave Detail: NE 2 ft at 4 seconds and SW 1 foot at
5 seconds.
.TONIGHT...NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to
3 ft. Wave Detail: N 2 ft at 5 seconds and SE 1 foot at
14 seconds.
.TUE...E winds around 10 kt. Seas 2 to 4 ft. Wave Detail: E 2 ft
at 4 seconds and S 2 ft at 16 seconds.
.TUE NIGHT...SE winds 5 to 10 kt. Seas 3 to 5 ft. Wave Detail: S
3 ft at 16 seconds and E 2 ft at 5 seconds.
.WED...E winds 10 to 15 kt. Seas 3 to 5 ft. Wave Detail: S 4 ft
at 15 seconds and E 1 foot at 5 seconds.
.WED NIGHT...E winds 10 to 15 kt. Gusts up to 20 kt after
midnight. Seas 4 to 6 ft. Wave Detail: S 5 ft at 16 seconds and E
1 foot at 4 seconds.
.THU AND THU NIGHT...NE winds 20 to 25 kt with gusts up to 30 kt.
Seas 5 to 8 ft.
.FRI...NE winds 20 to 25 kt with gusts up to 30 kt. Seas 4 to
6 ft.
.FRI NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Seas
3 to 4 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.

$$

ANZ234-190000-
Buzzards Bay-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 4 PM EDT THIS AFTERNOON...

.TODAY...NE winds 15 to 20 kt with gusts up to 30 kt. Seas 3 to
4 ft. Wave Detail: NE 2 ft at 4 seconds and SW 1 foot at
5 seconds.
.TONIGHT...NE winds 10 to 15 kt with gusts up to 20 kt,
diminishing to 5 to 10 kt after midnight. Seas 2 to 3 ft. Wave
Detail: N 2 ft at 4 seconds and SE 1 foot at 14 seconds.
.TUE...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: S 2 ft at
16 seconds and E 1 foot at 2 seconds.
.TUE NIGHT...SE winds 5 to 10 kt. Seas 2 to 4 ft. Wave Detail: S
3 ft at 15 seconds and E 2 ft at 4 seconds.
.WED...E winds 5 to 10 kt, becoming SE 10 to 15 kt with gusts up
to 20 kt in the afternoon. Seas 2 to 4 ft. Wave Detail: S 3 ft at
15 seconds and E 2 ft at 3 seconds.
.WED NIGHT...E winds 10 to 15 kt. Gusts up to 20 kt after
midnight. Seas 3 to 5 ft. Wave Detail: S 3 ft at 16 seconds and E
1 foot at 3 seconds.
.THU AND THU NIGHT...NE winds 15 to 20 kt, increasing to 20 to
25 kt. Gusts up to 30 kt. Seas 4 to 6 ft.
.FRI...NE winds 20 to 25 kt with gusts up to 30 kt. Seas 3 to
5 ft.
.FRI NIGHT...S winds 15 to 20 kt with gusts up to 30 kt. Seas
2 to 4 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.

$$

ANZ235-190000-
Rhode Island Sound-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 4 PM EDT THIS AFTERNOON...

.TODAY...NE winds 20 to 25 kt, diminishing to 15 to 20 kt this
afternoon. Gusts up to 30 kt. Seas 3 to 4 ft. Wave Detail: NE
4 ft at 4 seconds and SW 1 foot at 5 seconds.
.TONIGHT...NE winds 10 to 15 kt with gusts up to 25 kt. Seas 2 to
4 ft. Wave Detail: NE 3 ft at 4 seconds and SE 2 ft at
14 seconds.
.TUE...E winds around 10 kt. Gusts up to 20 kt in the morning.
Seas 3 to 5 ft. Wave Detail: E 3 ft at 6 seconds and SE 3 ft at
16 seconds.
.TUE NIGHT...SE winds 5 to 10 kt. Seas 4 to 6 ft. Wave Detail: S
5 ft at 16 seconds and E 3 ft at 7 seconds.
.WED AND WED NIGHT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas 5 to 8 ft. Wave Detail: S 8 ft at 16 seconds and E 2 ft at
6 seconds.
.THU AND THU NIGHT...NE winds 20 to 25 kt with gusts up to 30 kt.
Seas 9 to 12 ft. Wave Detail: S 12 ft at 17 seconds and NE 6 ft
at 6 seconds.
.FRI...NE winds 20 to 25 kt with gusts up to 30 kt. Seas 5 to
8 ft.
.FRI NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Seas
4 to 6 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.

$$

ANZ237-190000-
Block Island Sound-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 4 PM EDT THIS AFTERNOON...

.TODAY...NE winds 15 to 20 kt with gusts up to 30 kt. Seas 3 to
4 ft. Wave Detail: NE 3 ft at 4 seconds and S 1 foot at
5 seconds.
.TONIGHT...E winds 10 to 15 kt with gusts up to 25 kt. Seas 3 to
4 ft. Wave Detail: E 3 ft at 5 seconds and SE 2 ft at 14 seconds.
.TUE...E winds around 10 kt. Gusts up to 20 kt in the morning.
Seas 3 to 5 ft. Wave Detail: E 3 ft at 5 seconds and SE 3 ft at
15 seconds.
.TUE NIGHT...E winds 5 to 10 kt. Seas 4 to 6 ft. Wave Detail: S
5 ft at 16 seconds and E 3 ft at 6 seconds.
.WED AND WED NIGHT...E winds 10 to 15 kt with gusts up to 20 kt.
Seas 5 to 7 ft. Wave Detail: S 7 ft at 16 seconds and E 2 ft at
6 seconds.
.THU...NE winds 15 to 20 kt with gusts up to 25 kt. Seas 8 to
11 ft. Wave Detail: S 10 ft at 17 seconds and E 3 ft at
6 seconds.
.THU NIGHT...NE winds 20 to 25 kt with gusts up to 30 kt. Seas
9 to 13 ft.
.FRI...NE winds 20 to 25 kt with gusts up to 30 kt. Seas 6 to
9 ft.
.FRI NIGHT...S winds 15 to 20 kt with gusts up to 25 kt. Seas
4 to 6 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.

$$

ANZ230-190000-
Boston Harbor-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT THROUGH THIS EVENING...

.TODAY...NE winds 15 to 20 kt, diminishing to 10 to 15 kt this
afternoon. Gusts up to 25 kt. Waves 2 to 3 ft.
.TONIGHT...E winds 5 to 10 kt, becoming NE after midnight. Waves
1 foot or less.
.TUE...E winds 5 to 10 kt. Waves 1 foot or less.
.TUE NIGHT...SE winds 5 to 10 kt, becoming S after midnight.
Waves 1 foot or less.
.WED AND WED NIGHT...E winds 10 to 15 kt with gusts up to 20 kt.
Waves around 2 ft.
.THU THROUGH FRI NIGHT...S winds 15 to 20 kt with gusts up to
25 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.

$$

ANZ236-190000-
Narragansett Bay-
703 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 1 PM EDT THIS AFTERNOON...

.TODAY...NE winds 15 to 20 kt with gusts up to 30 kt, diminishing
to 10 to 15 kt with gusts up to 20 kt this afternoon. Waves 2 to
3 ft.
.TONIGHT...NE winds 5 to 10 kt. Gusts up to 20 kt in the evening.
Waves around 2 ft.
.TUE...NE winds 5 to 10 kt, becoming SE in the afternoon. Waves
2 to 3 ft.
.TUE NIGHT...SE winds 5 to 10 kt. Waves 2 to 4 ft.
.WED...E winds 5 to 10 kt. Waves 2 to 4 ft.
.WED NIGHT...E winds 5 to 10 kt. Waves 2 to 4 ft, except 4 to
6 ft at the bay entrance.
.THU THROUGH FRI NIGHT...S winds 15 to 20 kt with gusts up to
30 kt. Waves 2 to 4 ft, except 5 to 7 ft at the bay entrance.

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.

$$

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