Maryland

Purse State Park (Potomac)

Paleocene unicorn. The Aquia Formation here yields ~60 million year old shark teeth - vastly older than Calvert. Striatolamia striata and goblin shark cousins.

⚠ Partial inputs

today

Good

Cliff site — continuous erosion baseline · low tide during daylight · +4 seasonal event · best low 61

Today at a glance

Updated 2026-07-20T21:38:13.860Z

Solid hunting day. Best window opens around the 6:33 PM low (0.3 ft). Moderate SE winds (7 mph).

Heads up: a second low at 6:23 AM is after dark — bring a headlamp.

Next 3 days: Tomorrow is the pick (65); Wed runs cooler at 56.

Best Window Today

6:33 PM

Plan around the good low-tide window. Cliff site — continuous erosion baseline · low tide during daylight · +4 seasonal event · best low 61.

Hunt score

Good

Astronomical low

0.3 ft

6:33 PM

Predicted real low

0.3 ft

Near NOAA prediction

Low-window wind

1 mph

Light — negligible effect

Tides: NOAA Liverpool Point, MD (station 8578984)

Best window this week

Fri, Jul 24 · 9:53 PM

Light wind — near prediction

Score

Great

Confidence: Partial — noaa tide station, on-site outcomes. Hover the badge above for the input-by-input breakdown.

Tonight's moon

First quarter

44% illuminated

Sunrise 10:01 AM · Sunset 12:30 AM

Wind right now

7 mph from SE

Gusts 22 mph · best from S

Wind is mostly offshore — slightly more beach.

Past 7 days

Compare model output to your actual visits.

Next 7 days

Plan a trip →

▼ means the forecast wind will likely push the real low below NOAA's prediction (more beach to hunt). ▲ means it will likely sit above the prediction (less beach). Rough rule: ~0.04 ft per mph of sustained wind during the low-tide window.

Tide times: NOAA CO-OPS station 8578984 (Liverpool Point, MD) — local time, MLLW datum. Click to verify on NOAA. Cards show LOWS only (best for hunting); highs are visible on the tide curve below.

🌤️ Weather & Wave Forecast

Impact on visibility and stir-up over the next 5 days.

Onshore Wind: Pushes water in (tide sits higher) and stirs up the bottom. Good for "new" teeth, bad for visibility.

Offshore Wind: Water blown out (tide sits lower). Maximum beach exposure for hunting the low tide line.

Why today scores 61

Cliff sites score from a baseline plus recent storm stir, daylight low tide timing, wind exposure, and seasonal events (only when storms are actually shedding cliff material).

Best low

6:33 PM at 0.3 ft

Predicted real low

0.3 ft

Wind deviation

Less beach by 0.0 ft

Explain this scoreShow breakdown ▾

💡

Analysis

Solid. Reliable productivity expected.

Cliff baseline + tide depth

44.1 / 50

Constant 45 baseline (cliffs always shed) plus ±5 from how deep the best low actually pulls back.

Storm stir

2.4 / 25

Past 72h wind churn (peak gust 24 mph). Offshore = +, onshore = −.

Light at best low

9.0 / 9

Daylight low = +9, twilight = 0, headlamp-only = −9.

Wind exposure at best low

1.1 / 12

Wind setup piles 0.0 ft of water around the low.

Spring tide

0.8 / 5

Closer to a new or full moon = wider tidal swing.

Recent rainfall

0.0 / 12

No measurable rain in the past 48h — no slump signal.

Event boostadded

+15

Manual + auto events (storms, dredge work, drought). Scaled down on drowned-beach days.

Why not higher? The biggest unused headroom today is storm stir (+22.6 pts available). A day with that maxed out would score around 84.

Show the math

components: 44.1 + 2.4 + 9.0 + 1.1 + 0.8 + 0.0 = 57.4 + event boost +15 = 72.4 final = 72

What's NOT in this score

We are deliberate about which factors to include. These are not currently in the model:

Hunt pressure. A “hunts this week” chip is shown on each location page for transparency, but it does not change the score yet. We need more outcomes per site before a penalty would be statistically meaningful.
Wave period / swell direction. We use wave height only. Long-period groundswell sorts material differently than short wind chop, but Open-Meteo doesn't expose period reliably.
Barometric pressure trend. Falling pressure = approaching storm = building stir. Currently we wait for the wind to actually arrive.
Water temperature, clarity, salinity. Affects comfort but not (directly) what teeth wash up.
Weekday vs weekend. A 70 on Tuesday is often better in practice than a 70 on Saturday because of crowds, but we don't adjust for that.
Beach renourishment. Fresh sand buries everything. We capture this only when an admin logs a manual event — there's no auto-detection.

If you think we should add one of these, log a hunt with notes — every rated outcome helps us decide which signals actually predict tooth count.

Hunt Score

Sum of components + 15 event boost, clamped 0–100.

Score model 2026.04.29 · how this is calculated

Hunted here today?

Rate this hunt

We predicted 61. Tell us how it actually went — your rating calibrates the model.

model 2026.04.29

Checking what the moon's doing tonight…

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Event timeline

⚡

Calvert Cliffs Spring Freeze-Thaw Erosion Window

ended

Late winter freeze-thaw cycles destabilize the Chesapeake Group cliffs. March–early May historically produces the most fresh fall material on the beaches at Brownie's, Matoaka, and Westmoreland.

2026-03-01 – 2026-05-15

- Freeze-thaw cycles loosen cliff matrix

- First low tide after a heavy rain or nor'easter is prime

+10 pts

Geology

FormationsAquia Formation

EpochsPaleocene, Eocene

Age~60-55 million years

Star speciesOtodus obliquus

Technique

Walk the Potomac shoreline at very low tide. Most finds are small but ancient.

Access