CatchWindow fishing intelligence

Chatham, MA Daily Water Report — August 27, 2026

Diving takes top honors again today with an 8.7, but don’t let that single number fool you—this is a day for splitting up your time on the water based on what you’re chasing. The southerly breeze has picked up since yesterday, running 9 knots steady with gusts into the mid-teens, and that’s pushing a 0.58-meter wind-driven chop with a short 4.9-second period. The real story is the calm window early: seas bottom out around 0.38 meters near 7 a.m., which is your best bet for a smooth paddle or a tender boat launch. After that, the afternoon sees waves climbing toward 0.7 meters as the wind strengthens, and with a falling barometer and 100% cloud cover, the atmosphere feels like it’s holding its breath for something. Divers still have it made. The water sits at 20.1°C, barely a tenth below the long-term average, and conditions are consistent with what’s been a remarkably stable week for subsurface work—scores have hovered between 8.7 and 8.8 since the 22nd. Visibility likely remains decent given the modest swell and offshore current direction, though the high chlorophyll reading is worth noting as a sign of potential particulate matter near the surface. Surfers get a 6.5, a half-point improvement over yesterday’s 6.0 thanks to a longer-period 7.3-second swell from the southeast adding some organization to the mix. The 0.34-meter groundswell is small but has enough direction to work an outer bar if you’re patient. Sailing scores a 7.6, and that makes sense—consistent 9-knot breezes with occasional puffs are ideal for a reach or a beat, though the lumpy wind waves will keep you on your toes. Boating and kayaking sit lower at 5.8 and 4.8 respectively, pulled down by the building afternoon chop and that steady current running 2.3 meters per second toward the east. Wildlife observers get a middling 5.9, improved slightly from yesterday but still a far cry from the 7.4 posted on the 24th when the wind was lighter. Fishing at 6 is workable but not stellar; the morning solunar minor period from 4:28 to 5:28 aligns with dawn and calmer seas, making that the prime hour to wet a line before the breeze takes hold. Looking ahead, Friday brings lighter winds under 8 knots and smaller waves around half a meter—better for boating and maybe a repeat of today’s diving score. Saturday cools off but stays calm with peak winds climbing back to 12 knots. The real change arrives Monday: a cold front swings through, dropping afternoon highs to just 18.7°C and kicking up winds to 15.5 knots with a 26% shot at rain. Tuesday sees the biggest seas of the forecast period at nearly a meter, so if you’ve got a trip to the back side planned, sooner is smarter than later. Best bet: Get out for dawn patrol—that 7 a.m. calm is your one-hour pass to smooth water before the south wind starts writing its own script.