AlgoCatch vs Navionics vs Fishbrain: which app for Adriatic fishing?

AlgoCatch vs Navionics is a job split: navigate with that chart or a rival, log catches with Fishbrain, and plan depth, Folk-5 seabed and species habitat with the Adriatic fishing planner. They complement each other; only one plans the bottom.

Updated 2026 — rival facts checked 18 September 2026.

Which fishing app should you use on the Adriatic?

Navigation and harbour approach: Navionics or the other major chart brand. Logging and sharing catches: Fishbrain. Deciding where to cast, anchor or troll from depth, seabed class and species habitat: AlgoCatch. Most Adriatic anglers need a chart plus a planner, not a winner.

Fishing apps sold for a Croatian or Slovenian week are not substitutes. A navigation chart is assembled from official hydrographic objects, aids to navigation, marinas and tides so you can move a boat. A social catch log is assembled from user-reported catch pins and a feed so you can record what you already caught. An Adriatic fishing planner is assembled from bathymetry, substrate classes and a species-by-technique model so you can decide where to fish before you leave the car or the berth. Generic rankings collapse those three product categories into one score; the Pre-trip comparer actually chooses by job and by trip length.

The mechanism is the data, not the icon. Crowd-sourced soundings and chart objects answer whether a passage is charted. A pin answers whether someone once reported a fish. A habitat model answers whether this depth and this bottom class fit this species and this technique. Those are different questions. Navionics vs Fishbrain looks similar in an app-store grid and is not similar on the water.

Evidence is dated. The Boating product page (checked 18 September 2026) describes marine charts, overlays, tides and a subscription after a free trial (vendor T4). The catch logbook page (checked the same day) describes catch logging, photos and a Pro subscription (vendor T4). AlgoCatch, for Trieste–Ancona, the Slovenian coast, Istria, Kvarner and Dalmatia, shows a planning depth grid, Folk-5 classes and habitat scores from Poor to Hot. The planner is not a navigation chart; the score is not a fish count.

Apply it by trip, not by brand loyalty. A one-week shore visitor from the UK, Germany, Austria or the Netherlands opens AlgoCatch Free — or the seven-day pass if they want every species — then buys the Croatian recreational licence only at ribarstvo.mps.hr. A boat week keeps the chart you already trust for the passage and opens the planner for the fishing edge. A local who already traces contours keeps that chart and adds the planner for substrate and species. The best fishing app for Croatia is the stack that matches tonight’s decision, not a single winner.

What is each app built for?

Navionics (Garmin since 2017) is a navigation chart with aids to navigation, marinas and tides. Fishbrain is a social catch log with spot pins. The other commercial chart brand is a navigation chart. AlgoCatch is an Adriatic planner: depth, Folk-5 seabed, habitat scores.

Four products sit in three categories. Roundups blur them because each app shows a map; the maps are not the same object. One family is built around official charts plus crowd soundings. One is built around user catch pins. One is built around bathymetry, substrate and a habitat model. Read the row that matches the job you need tonight, then stop. Feature tours belong on the cluster pages, not here.

App	Owner	Category	Core data	Pricing model
AlgoCatch	AlgoCatch	Adriatic fishing planner	Planning depth, Folk-5 seabed, species habitat scores — [what an Adriatic fishing map shows](/en/chart/what-the-chart-shows)	Free with no card; 7-day pass
Navionics	Garmin (since 2017)	Navigation chart (Boating)	Aids to navigation, marinas, tides; SonarChart crowd-sourced contours	Subscription after a free trial
Fishbrain	Independent	Social catch log	User catch pins, photos, social feed	Free tier plus Pro subscription
C-MAP	Navico group	Navigation chart	Official-chart objects, contours, marinas, tides	Subscription after a free trial

The ownership facts are what make the concessions credible. The 2017 acquisition notice states the chart brand was acquired in October 2017 (corporate T4, checked 18 September 2026). The group brand page (checked the same day) presents the second chart as a group navigation product (vendor T4). The logbook vendor presents itself as a social fishing app with a free tier and Pro, not as an Adriatic bathymetry publisher (vendor T4). AlgoCatch is a web planner for this sea only; native apps are not required to plan tonight — the map runs in a phone browser.

If you need to move a boat, open a navigation chart. If you need to keep a diary of what you caught, open the social catch log. If you need to choose a depth band and a bottom class for gilthead, dentex or a trolling line before you leave the apartment, open the fishing planner. The identity table is the whole argument of this section; later sections prove one cell at a time.

Which app shows the seabed type for fishing?

Only AlgoCatch shows a continuous seabed layer: EMODnet Geology Folk-5 classes (mud to muddy sand, sand, coarse, mixed, rock and boulders). The two navigation charts show point bottom abbreviations from official charts; the social catch log shows no seabed at all.

This is the attribute local structure anglers actually argue about, and it is not “who has bottom data”. Official nautical charts print bottom-quality letters at isolated soundings — S, M, R and their compounds — so a skipper can judge holding ground under a marked anchorage. That is a point sample. A Folk-5 seabed class map is a continuous polygon layer: every cell in the coverage box carries one of five classes. Asking a point abbreviation whether a whole bay is sand or rock is the wrong document.

The mechanism follows the source. EMODnet Geology harmonises national substrate datasets onto a modified Folk scheme: mud to muddy sand, sand, coarse substrate, mixed sediment, rock and boulders. AlgoCatch draws that layer as the continuous seabed layer an angler taps before a session. Navigation charts reproduce the official-chart bottom-quality symbols that sit on those products’ legends (vendor T4, checked 18 September 2026). They have point notes. They have no continuous Folk-5 sediment map. The social catch log has neither notes nor polygons; its map is a pin field.

Do not read that as “the chart is empty under the keel”. A point note under a charted anchorage is still the right object for holding ground. It is the wrong object for deciding whether a 400-metre stretch of Istrian shore is sand or rock before you walk it at 18:00. For that, open the Folk-5 seabed class layer. For the abbreviation under a marked symbol, keep the chart. What each Folk-5 class means for fishing — which species sit on which class — is a different article; this page only names the five classes and the continuous-versus-point split. what each Folk-5 class means for fishing

Which app has better depth contours for the Adriatic?

For fine contours near busy harbours, SonarChart's crowd-sourced high-definition layer usually wins. AlgoCatch uses the uniform EMODnet Bathymetry grid (about 115 m), which reads structure across the whole coast but is a planning depth, not a navigation depth.

The honest comparison is a trade-off, not a knockout. Crowd-sourced high-definition contours accumulate where boats travel: approaches, fairways, and the water in front of busy harbours. A uniform digital terrain model is compiled once for the whole basin at 1/16 arc-minute, so a quiet bay on Cres is gridded on the same rule as the water off Rovinj. Density that follows traffic is a strength where traffic is dense and a silence where it is not. Uniformity is the opposite strength. This page therefore concedes SonarChart near busy harbours and still sends the fishing-edge decision — especially on a quiet Dalmatian or Slovenian-coast stretch — to the uniform grid.

SonarChart is described on the Boating charts feature list as HD bathymetry enhanced by boater-contributed sonar logs (vendor T4, checked 18 September 2026). EMODnet Bathymetry publishes a DTM at 1/16 × 1/16 arc-minute, about 115 m, covering European seas including this one (DTM 2024 release, T1). AlgoCatch reads that EMODnet Bathymetry grid as planning depth; near-shore cells are mixed-resolution, and the product does not claim chart-scale accuracy. At Rovinj harbour in August 2026 the SonarChart layer drew more contour detail than the planner (T3, observation — not a measured error in metres, and not a claim that the planner is “wrong”).

Use the crowd-sourced layer when you need fine shape next to traffic. Use the planner’s contours plus Folk-5 when you need a fishing edge that still exists on a quiet stretch of Dalmatia or the Slovenian coast. Then verify the number under the boat. The fishfinder vs fishing map question is the verification step, not a feature war. For what the crowd-sourced layer shows and misses as a fishing tool, see what Navionics SonarChart shows and misses for fishing.

Which app scores a fishing spot by species and technique?

Only AlgoCatch: a habitat suitability score per species and technique from depth and Folk-5 seabed, shown Poor to Hot. The navigation charts offer fishing-range depth shading only; the social catch log shows past catch pins, not habitat. No app counts fish.

Roundups call all three things “spots”. They are not the same data type. A habitat suitability score is a model: depth plus Folk-5 seabed class plus a species-and-technique preference, displayed Poor to Hot. It says whether the bottom fits the fish. It is not a fish count and not a prediction of tonight’s bag. Fishing-range depth shading is a filter on a navigation chart: you colour a depth band you care about; nothing in that colour says gilthead or dentex or trolling. Catch pins are a diary: someone reported a fish at a coordinate. On the Croatian coast those pins, as a pattern, cluster around harbours and tourist spots (T3/T5) — useful as history, silent as habitat.

The Boating listing (checked 18 September 2026) includes map options to target fishing ranges; it does not describe a species habitat model (vendor T4). The logbook product page (checked the same day) is built around logged catches, not an Adriatic substrate-and-depth score (vendor T4). what Fishbrain's spot map really shows in Croatia owns the pin pattern in detail. AlgoCatch computes the score from the two layers already named and the species-technique pair you select. Weights and tier cut-offs live on the score pillar, not here.

Shortlist by the score, then verify depth on the water. Treat pins as a record of where anglers stood, not as a map of where the bottom is right. If a pin sits on a harbour wall and the Folk-5 class you need is 300 metres farther out, believe the class. A shaded depth band on a chart is still only a filter: it does not name a species and it does not score a technique. No app shows where the fish are. how the habitat score works

Which app plans trolling, anchor and longline sessions?

AlgoCatch has trolling, anchor and longline modes on Free: contour-band trolling routes, anchor zones on structure edges, longline bands on sand and mud. Navionics routes are for navigation, not technique. The social catch log has no route planning.

Routing and technique planning are different products that share the word “route”. A navigation route minimises hazards between waypoints: depth under the keel, aids, a suggested track from berth to berth. A technique mode scores a contour band, a structure edge or a bottom class for a way of fishing. Keeping a lure in one depth band over the right Folk-5 class is not the same task as drawing a safe track. Confusing them is how boat visitors buy a chart, run autorouting, and still troll empty water.

The Boating listing (checked 18 September 2026) describes automatic dock-to-dock guidance from chart data and navigation aids, and states that this guidance is for planning a passage, not a substitute for safe operation (vendor T4). That is navigation routing. AlgoCatch on Free offers three technique modes — trolling, anchor, longline — and on VIP three more: shore jigging, surfcasting, spearfishing. The free modes suggest a trolling band on contours, an anchor zone on a structure edge, or a longline band on sand and mud. They do not replace a plotter, and this page does not teach speeds, rigs or how to place an anchor. The VIP trio is still a planning choice: it names a shore or spear session against structure, not a safe track between berths.

Plan the trolling, anchor or longline session in the planner the evening before. Load the waypoints you accept into the plotter you already pay for, and run the passage on the navigation chart. If you came to spin from the rocks or to hunt with a spear, that is the VIP trio — still a planning choice, still not a navigation track. which technique fits an Adriatic bay

Attribute	AlgoCatch	Navionics	Fishbrain	C-MAP
Seabed layer	Yes — continuous Folk-5	Point notes only	No	Point notes only
Contours	Yes — ~115 m planning grid	Yes — crowd-sourced HD	No	Yes — chart contours
Species score	Yes — Poor to Hot	No	No	No
Technique routes	Yes	No	No	No
Navigation	No	Yes	No	Yes
Catch log	No	No	Yes	No

What does each app cost for a one-week Adriatic trip?

AlgoCatch: Free with no card, or the €5 Week Pass for 7 days of every species and unlimited routes. The two chart brands are subscriptions after a trial; Fishbrain has a free tier and Pro; rival euro figures are omitted unless checked on publication day.

For one week the pricing models differ more than any number on a screenshot. A holiday visitor needs seven days of planning, not an annual contract they will forget in November. A local already paying for a chart needs to know what they add, not a fake “winner costs less” table. Roundups quote stale store prices; this page will not invent one.

AlgoCatch is Free with no card, or Week Pass €5 for 7 days. That is the only price this article states. The Boating product page and the second chart’s site (both checked 18 September 2026) sell access as a subscription after a free trial (vendor T4). The social catch log sells a free tier plus a Pro subscription (vendor T4, same date). No rival euro figure appears here because a store price that is not copied on publication morning is a rumour.

A one-week visitor who only needs gilthead, depth and the three free modes stays on Free. A visitor who wants every species and unlimited routes for the holiday week takes the seven-day pass. If they also skipper a rented boat, they still need a chart trial or subscription for the passage — that cost is on the vendor’s page, not invented here. What a free fishing map for Croatia gives you across brands, including trial length, is a cluster article. This page’s only pricing link is the plans pillar. what a free fishing map for Croatia gives you. Plan facts beyond Free and the seven-day pass live on AlgoCatch plans and prices.

Can you use Navionics and AlgoCatch together?

Yes. Plan the session in AlgoCatch (depth band, seabed class, habitat score, technique), then navigate with the chart you already use and official charts. Log the catch in Fishbrain if you like.

The tools stack; they do not compete. Comparisons that force a single winner hide the workflow most Adriatic boat weeks already run: decide the fishing edge the evening before, move the boat on a navigation chart and official paper or plotter charts, and optionally write the catch down. AlgoCatch is not a navigation chart. It does not carry aids to navigation as a plotter layer, and it is not the document you steer by. The Boating product remains the navigation chart for that job (vendor T4, checked 18 September 2026).

The mechanism is sequence, not preference. The planner outputs a depth band, a Folk-5 class, a suitability reading and a technique mode. The chart outputs a passage you can actually run. The social catch log outputs a record. Each step uses the data type from the identity table. Mixing them — steering on a planning grid, or picking a trolling band from a catch pin — is how the stack fails. The document-type distinction, brand aside, is fishing map vs nautical chart.

On 12 August 2026 Lenart ran a trolling day out of Cres in Kvarner. The evening before, at 21:00, we shortlisted a contour band and a Folk-5 class in the planner, then the next morning the passage sat on the plotter chart, and the two fish we chose to remember went into the social log after the engine was off. That is plan in AlgoCatch, navigate with Navionics, log if you want a diary. Do the same on a Kvarner boat week: decide the edge before you sleep, run the boat on the chart you already paid for, and do not ask the planner to be a plotter.

How do C-MAP, Fishing Points and FishFathom compare?

C-MAP is a Navico navigation chart, close to the first chart brand for Adriatic contours and equally without seabed classes or species scores. Two forecast-and-pin apps offer spot pins and weather or tide forecasts, but no Adriatic seabed layer or habitat score.

The long tail of “which app for Croatia” is still the same three categories. The second chart brand is a navigation chart: official-chart objects, contours, marinas and tides, sold as a subscription after a free trial (the vendor site and the group brand page, checked 18 September 2026, vendor T4). Apply the two-attribute test used above: continuous seabed layer, species score. It has neither. If your plotter already runs that cartography, keep it for navigation. Chart-by-chart contour differences belong on C-MAP vs Navionics for Adriatic anglers.

One pin-and-forecast vendor (checked 18 September 2026) publishes maps, tides, weather and a catch log (vendor T4). The other (checked the same day) publishes waypoints, forecasts and planning tools (vendor T4). Neither page, on that date, offered an Adriatic Folk-5 seabed layer or a Poor-to-Hot suitability reading. Use them for weather or a pin you already trust; do not use them as the bottom map. Feature depth, forecast lists and coverage claims sit on Fishing Points and FishFathom on the Adriatic.

If you already pay for that chart, keep paying for navigation on the water this week. If you already like a forecast app, keep it for wind and tide. Open the Adriatic fishing planner when the decision is the bottom: class, depth band, species, technique. That is the whole long-tail answer; there is no fourth category hiding in a store screenshot. The same two-attribute test sorts any extra store brand.

Do not pick a single winner by store rank. Open the free planner on the bay you will actually fish, read the Folk-5 class at that point, and treat a mismatch with the species you came for as a go / no-go before you leave. Buy the licence at the official shop. If the trip is seven days and you need every species, take the €5 seven-day pass; if you skipper a boat, keep the navigation chart you already trust and do not steer on the planning grid. Start Free, no card, at app.algocatch.com.