Understanding tides for fishing is crucial for any serious surf angler. Tidal movements are one of main influences on baitfish behavior, when predators feed, how available food items are, what inshore currents are doing and – very often – when the best opportunities arise to catch fish from the beach, pier or shoreline.
While your local tide charts provide a general overview, they don’t give a minute-by-minute breakdown of how fast or slow the water is moving at any given time, making it easy to miss out on key feeding times aligned with peak tidal movement.
That’s where the Rule of Twelfths comes in.
This simple but effective rule helps predict how much the tide will rise or fall in each portion of a tidal cycle, allowing inshore and surf anglers to time their sessions for peak movement when lots of fish are most active.
From many years of fishing experience all around the world, and guiding for lots of surf species in California, the idea of current being a positive factor is nearly universal, but none more so than in the nearshore surf environment.
Here's how to use the rule to time your next beach fishing sessions for maximum success.
The Twelfths Rule Explained for Tides and Fishing Success
Let's use a simple tide cycle from low tide to high tide taking approximately six hours as an example for ease of explanation. Whilst acknowledging the massive variation in size and times of tides across the USA's coastlines, this is the easiest way to demonstrate how this rule basically operates.
The Rule of Twelfths states that tidal movement is not uniform—water moves slower at the beginning and end of the cycle, and fastest in the middle.
Here’s how that movement breaks down over that six hour swing:
Hour 1: 1/12 of total tidal movement
Hour 2: 2/12 of total tidal movement
Hour 3: 3/12 of total tidal movement
Hour 4: 3/12 of total tidal movement
Hour 5: 2/12 of total tidal movement
Hour 6: 1/12 of total tidal movement
This means that the third and fourth hours of the cycle should experience the most water movement – around 1/2 of the total tidal movement in only 1/3 of the time (2 hours) The bar chart below illustrates this peak visually.
This peak often makes that middle third of the cycle prime-time for fishing as food items such as baitfish, crustaceans, shellfish, worms and plant matter get stirred up with increasing currents, and fish come closer to shore to take advantage. Predators can also feed by scent far easier in a current, hunt faster and ambush prey that's not as agile or strong.
Many such fish living close to shore and in areas with tidal movements, have evolved and adapted to feed around these stronger currents because this is when the most food is available to them for the least effort. Think of a shark hunting in shallow, fast-moving water – or a striper using the tidal currents to its advantage when hunting baitfish.
It's a common misconception that lots of species prefer feeding in the calmest conditions possible. Maximum food for the least effort is the equation the fish are gaming, and current is helpful to the fish, and thus to us as the angler hunting the fish.
There are exceptions; some larger rays and skate seem to prefer slacker periods in the tide cycle, as do some trophy fish that are maybe hunting in a slightly different way due to size, wariness or dietary preferences. No hard rules in fishing.
West Coast Pacific Ocean Example: Best Tides for Fishing
Another factor to consider on the Pacific Coast, particularly along California and Oregon, are the mixed semi-diurnal tides.
Mixed semi-diurnal tides means there are usually two high tides and two low tides per day, but the heights of the tides vary, with one set higher and the other lower. Below is an example of such a tide in California.
As a real West Coast example, let's use the above early-morning incoming (flooding) tidal swing of around 5 feet, a handful of days before a full, first quarter or new moon – a typical day you might target to go surf fishing in early spring in California. And let's use 6am to 12-midday and 0ft to 5ft as the time and height measurement for ease of calculation, thus:
Low tide: 0.0 feet at 6:00 AM
High tide: 5.0 feet at 12:00 PM
Total rise: 5.0 feet over six hours
Applying the Rule of Twelfths:
6:00 - 7:00 AM: 0.42 ft rise (0.42 ft total)
7:00 - 8:00 AM: 0.83 ft rise (1.25 ft total)
8:00 - 9:00 AM: 1.25 ft rise (2.50 ft total)
9:00 - 10:00 AM: 1.25 ft rise (3.75 ft total)
10:00 - 11:00 AM: 0.83 ft rise (4.58 ft total)
11:00 AM - 12:00 PM: 0.42 ft rise (5.0 ft total)
Using this rule, for surf fishing on the West Coast, the 8:00 AM to 10:00 AM window provides the strongest water movement, very likely attracting species like striped bass, leopard sharks, croaker, corbina and surf perch, which feed aggressively in strong currents near shore.
East Coast Atlantic Ocean Example: Finding the Best Tides for Fishing
Let's look at a scenario on the East Coast with much more moderate tidal swings, using one of the New York tide stations as an example.
Also leveling out the tide height and times a tide for ease of calculation so it looks like this:
Low tide: 1.0 feet at 3:00 PM
High tide: 4.0 feet at 9:00 PM
Total rise: 3.0 feet over six hours
And using the Rule of Twelfths:
3:00 - 4:00 PM: 0.25 ft rise (1.25 ft total)
4:00 - 5:00 PM: 0.5 ft rise (1.75 ft total)
5:00 - 6:00 PM: 0.75 ft rise (2.50 ft total)
6:00 - 7:00 PM: 0.75 ft rise (3.25 ft total)
7:00 - 8:00 PM: 0.5 ft rise (3.75 ft total)
8:00 - 9:00 PM: 0.25 ft rise (4.0 ft total)
Using the Rule of Twelfths, in this situation the strongest tidal currents will likely occur between 5:00 PM and 7:00 PM, when water movement peaks.
How to Apply the Rule of Twelfths for Surf Fishing Success
By understanding and applying the Rule of Twelfths, anglers can optimize their surf fishing trips to coincide with peak tidal movements and maximize time on the water for many commonly-caught species. Here are your five key steps:
Check Local Tide Charts: Identify high and low tides specific to your fishing location.
Use the Rule of Twelfths: Estimate hourly tidal changes to pinpoint peak water movement.
Plan Fishing Around Peak Movement: Fish during the hours of the tide cycle when currents are strongest. If you can line this up to be around dawn or dusk, even better.
Target Species That Thrive in Tidal Currents: Fish like striped bass, red drum, bluefish, surf perch, calico bass, corbina, leopard sharks and most game fish are active in fast-moving water, chasing baitfish and high-value food items.
Factor in Local Conditions: Coastal topography, seasonal weather, and swell can impact water movement, so always adjust accordingly and know your local spots well.
Other Factors To Consider
Wind Strength: A strong wind off or onshore can impact how the tide fills in. It might delay a peak push or retreat, especially in the afternoons when strong gusts can create wind swell that also impacts currents and water movement alongside the tides.
Proximity to Jetties and Harbors: Depending on the size and complexity of the waterway connected to an inlet, this can create its own unique tide with water taking much longer to start retreating out of large systems, often in a way that's out of sync with the usual tide tables.
Know your local inlets and visit them regularly at low, mid and high tides to get a feel for how they behave in each tide scenario. Often, the bigger the harbor or inlet, the wackier the tides coming in and out of it. Work those peaks whenever they may be.
Whether you're fishing the dynamic Pacific shoreline or the structured currents of the Atlantic, understanding tides for fishing through the Rule of Twelfths can significantly increase your chances of landing the quality fish that relish feeding in these gnarly conditions. Hopefully this concept will help you catch more fish next time you hit the water!
Author Ben Hervey-Murray is a surf fishing guide based in Southern California, and a member of the USA Surf Fishing Team.
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