FSLE, a true game-changer for pelagic fishing

TZ Professional introduces the new Finite Size Lyapunov Exponents (FSLE) data into the Premium Ocean-O service for pelagic fishing. This data is geared towards commercial fishermen and advanced sport fishermen who want to target the best fishing potential spots. It helps detect oceanic fronts where water masses converge or concentrate. These fronts are aggregation zones for plankton and small fish, attracting the predators you’re targeting (tuna, swordfish, mackerel, etc.)

What is FSLE — and Why It Matters to Fishermen

FSLE (Finite-Size Lyapunov Exponent) is an advanced oceanographic data layer that reveals how the ocean is moving, not just what its surface conditions look like. It highlights areas where water masses converge, stretch, and separate, forming dynamic features such as fronts, eddies, filaments, and convergence zones.

These ocean features are critical because they control how nutrients, plankton, and bait are concentrated and transported. Where water converges, life gathers. Where it stretches and separates, boundaries form. If you’ve heard terms like convergence flow, weed lines, or filaments, FSLE is the tool that lets you see them clearly and in real time, overlaid directly on your marine chart in TZ Professional PC software.

Turning Ocean Dynamics into Fishing Advantage

FSLE is an exclusive data layer available with the Premium Ocean-O Service, designed for commercial operators and serious sport fishermen who want to fish smarter, not wider.

Unlike traditional data layers that display individual variables such as sea surface temperature, currents, or chlorophyll, FSLE reveals ocean behaviour. Derived from ocean current data, it identifies exactly where water is converging or stretching, pinpointing productive fronts where nutrients and bait concentrate.

These zones are natural feeding highways — attracting baitfish, which in turn draw top predators such as tuna, marlin, and mackerel.

Why is it useful for fishing?

High FSLE values often align with concentrations of biogeochemical tracers, such as chlorophyll, plankton, and weed line, which attract predators. But high FSLE values do not necessarily occur where the strongest currents are, because FSLE measures how quickly water particles converge. The result is that you will discover unexpected high-potential fishing spots by integrating this data into your prospecting. That’s the incredible feedback we got from our best Beta Testers.

Pelagic Fisheries:

FSLE highlights areas where biogeochemical tracers, such as chlorophyll, plankton, and weed line, might concentrate, making it crucial for identifying productive fishing zones. Thanks to TZ MAPS and the Ocean-O Workspace in TZ Professional, it is easy to display FSLE and combine it with other types of data. FSLE maps can reveal regions of strong mixing or retention, which are critical for understanding the distribution of nutrients and marine life.

Fisherman testimony:

Dan Govier, an enthusiastic and top-level fisherman in New Zealand, shared with us: “I am finding the FSLE very interesting, and I am quickly developing trust in it as an area to predict where the fish were. As per my feedback last week, the big schools of bait fish and pelagic fish were found on the ocean front, in an area where you would not have predicted based on SST alone. This is mind-blowing, and I cannot stop thinking about it and how powerful this new information can be for fishing."

About Us:

Taylor Marine SOUTH AFRICA is the exclusive distributor for Furuno and TimeZero, supplying industry-leading marine electronics, navigation software, services, and subscriptions. We provide end-to-end solutions, from sales and system design to professional installation, commissioning, and ongoing service, supporting commercial and sports fishing vessels with reliable, best-in-class technology.

For information on TimeZero Professional, Ocean-O and FSLE contact our sales team: sales@taylormarine.co.za or Tel: 021 418 0022