Best Spearfishing Apps: Navigation, Species ID, Weather, and Logbooks

25 years ago a dive day started with a paper tide book, a laminated chart, and whatever the local radio station said about the wind. Today most divers walk down the ramp with eight open apps on their phone and a GPS watch on their wrist. That is not necessarily progress. Used well, mobile apps shorten the gap between a guess and a decision. Used badly, they turn a perfectly good plan into analysis paralysis at 5 a.m. in the parking lot.

This guide walks through the app categories that matter for breath hold hunting in California and beyond: weather and conditions, dive forecasting, navigation, species and regulations, logbooks, tides, waypoints, breath hold training, and dive computer companions. The goal is not to install everything. It is to pick the two or three apps in each category that actually influence decisions, and to understand the limits of what a phone can tell you about the ocean.

Why mobile data matters for the modern diver

Breath hold hunting rewards patience and punishes bad days. The difference between a fifteen foot visibility morning and a four foot visibility morning is the difference between a stringer and a drive home with nothing. Real time apps let you check buoy readings, swell period, wind vectors, and satellite chlorophyll on the drive to the ramp, so you can cancel a trip before you burn a tank of gas or redirect to a sheltered cove that the conditions actually favor.

The other reason to invest in good apps is safety. A phone with offline charts, a shared location, a float plan, and a working weather radar is a second layer of protection behind your float, your dive flag, and your partner. It does not replace any of those things. It does make the consequences of a bad decision smaller.

Weather and ocean conditions apps

Windy.com is the baseline. It aggregates multiple model outputs (ECMWF, GFS, ICON, NEMS) and lets you toggle wind, gusts, swell height, swell period, swell direction, and sea surface temperature on a smooth interactive map. For planning a two or three day window, Windy is the fastest way to see whether a front is coming or a swell is building. The paid premium tier unlocks hourly resolution and a one kilometer model that matters along complex coastlines like the Channel Islands and Big Sur.

Surfline is the surf industry standard and it earns its keep for divers in two ways: the cam network and the long range swell forecast. If you can watch live video of your dive spot at dawn, you know more than any model will ever tell you. The sixteen day LOLA swell model is also the most digestible way to see how a storm in the North Pacific will eventually reach your cove.

MSW (Magicseaweed, now folded into Surfline) still runs as a forecast tool and has loyal users who prefer its cleaner chart interface. Between Surfline and MSW you have the two most mature surf forecasting products in the world, and both are useful for divers who care about swell period and wave direction.

The NOAA Buoy Data app (or the free NDBC website in your browser) is the one most experienced divers keep open. Buoys do not forecast. They measure. A 46053 East Santa Barbara reading of 3 feet at 14 seconds is a real, live number that no model can argue with. Cross referencing a Windy forecast against a live buoy report is the fastest way to know whether to trust the model or throw it out.

WillyWeather is a quieter option with excellent tide and wind graphs, useful for planning slack currents around points and kelp edges. Stormglass is the aggregator that powers a lot of marine apps behind the scenes and is a fantastic source of raw data if you like building your own spreadsheets or custom dashboards.

For data quality: buoys beat models every time for current conditions, Windy and Surfline are roughly tied on 48 hour forecasts, and all models get unreliable past 72 hours in a complex coastline. If you only check one thing before leaving the house, check a buoy. If you only check one forecast, check the one whose model you have back tested against your own dive log.

SpearFactor Dive Conditions

The missing piece in every general weather app is translation. Windy tells you there is an eight foot swell at ten seconds out of the west. It does not tell you what that means for underwater visibility at your dive spot tomorrow at 8 a.m. That translation is what SpearFactor Dive Conditions was built to do.

The tool lives at conditions.spearfactor.com and was built for California divers after a string of wasted trips and missed windows. It ingests wind, swell, surface temperature, chlorophyll, recent rainfall, and buoy data, then produces a visibility estimate and a fish activity read for specific California dive locations. Under the hood it is pulling from the same free public sources as every other app (NOAA, NDBC, Open-Meteo, CMEMS, ERDDAP) but it combines them into a single dive specific answer instead of making you interpret five different charts.

Reports from the field over the last year have come back consistently within one to three feet of actual measured visibility, which is well inside the accuracy you would get from any general weather app (none of which even attempt a visibility number). If you spear in California and your phone only has room for one dive specific tool, this is the one we recommend.

Navigation, bathymetry, and charted reefs

Navionics Boating is the long time leader for recreational marine navigation and the reason a lot of us know our favorite reefs down to the foot. The depth contours, SonarChart community uploads, and points of interest are genuinely useful for finding kelp edges, pinnacles, and drop offs that do not show up on standard maps. The subscription covers most of North America.

Garmin ActiveCaptain is free and the natural choice if you already own a Garmin plotter on your boat. The community reviews and waypoint sharing are the strongest features. Offline chart downloads are essential if you plan to dive out of cell range.

iFish is popular with rock fish and halibut anglers and carries over well for divers who want annotated bottom structure with user shared catch data. AquaMap is a strong alternative to Navionics with excellent NOAA chart integration and lower ongoing cost for US only users.

For shore divers the real value of these apps is bathymetry. Knowing that a cove goes from ten feet to forty five feet in the length of a football field tells you where the structure is, where current is likely to bend around a point, and where bigger fish might be holding deeper off the rocks.

Species identification and regulations

Misidentifying a fish is the fastest way to turn a good day into a citation or a fine. California regulations are specific down to sub species in some groups (rockfish are the obvious example) and you do not want to be thumbing through a laminated card on a bouncing boat.

Fish Rules is the most important app in this list for any California diver. It geolocates you, asks what you caught, and tells you whether the species is legal, what the size limit is, what the bag limit is, and whether the season is open. Updates track in season regulation changes including the rockfish depth closures that shift from year to year. Install it before your next trip.

CDFW (California Department of Fish and Wildlife) publishes its own fish ID resources and the official ocean sport fishing regulations document in app and PDF form. The California Fish Species app is a lightweight photo based ID reference focused on state waters, useful for quickly separating similar looking species like gopher rockfish and black and yellow rockfish, or ocean whitefish and sheephead juveniles.

Google Lens is surprisingly good as a backup. Photograph a fish (or an old photo on the boat ride home) and it will pull visually similar species across the internet. It is not authoritative, but it is a great first pass when you know you saw something unusual and want to narrow down a name.

iNaturalist is the citizen science platform that doubles as a species ID tool. Upload a fish photo and a community of biologists and serious naturalists will confirm or correct your ID, often within hours. It is also a quiet way to contribute to marine science by logging your observations.

Logbooks and dive tracking

A dive log is the single most useful long term tool a diver owns. Over a year it teaches you which swell directions work your home coast, which tide phase holds fish at your favorite cove, which moon phases correlate with white sea bass pushing in, and which water temperatures shut everything down.

Dive Log (by GD Software) is the most established mobile logbook, widely compatible with dive computers and flexible enough for both scuba and breath hold entries. Subsurface is the open source option preferred by technical and freediving communities; it is free, runs on desktop and mobile, and supports an enormous range of computers. Diviac is a clean modern alternative focused on photos, stats, and shareable trip reports. MySSI is the logbook tied to SSI certification and is the right choice if you train within that agency.

The best log is the one you actually fill in. If that is a notes app on your phone, that is better than an abandoned Subsurface install. The fields that matter are: date, location, start and end time, water temp, visibility estimate, depth range, species seen, species landed, and weather and swell summary. Five lines a trip is enough to build a multi year pattern.

Tide, moon, and solunar apps

Tide and current data is free public information, which is why the apps in this category vary mostly in interface rather than accuracy. Tide Alert (NOAA) pulls directly from NOAA stations and is a clean no nonsense reader. MyTide offers good graphical tide charts and solunar overlays for anglers who track moon phases seriously. Solunar apps push the theory that bite windows peak around moonrise and moonset; the evidence is mixed, but the data it shows (tide phase, moon phase, sunrise, sunset) is free and useful even if you do not buy the theory.

For diving specifically, the tide data that matters most is the swing between low and high on a given day. Big tidal swings drive stronger currents around points and through channels, which can pull bait and gamefish through predictable lanes. A quick morning glance at a tide chart tells you whether to plan for a slack window or for current driven drifts.

GPS and waypoint apps

Gaia GPS is the most serious offline mapping app available to consumers. It is aimed at backcountry hikers and overlanders, but the same features (downloaded topographic maps, custom waypoints, shareable tracks) make it a strong phone tool for shore divers working remote coastline. Track your hike down, drop a waypoint at the water entry, mark the exit, and you have a GPX file for the next trip.

iBoating is a marine specific option with worldwide NOAA and CMAP chart coverage and is a decent middle ground between Navionics and Gaia. Navily is a cruiser focused app that shines when you are planning anchor locations, coves, and overnight spots; divers working from small boats overnight at the Channel Islands will find it useful.

Fitness and breath hold training

Breath hold training is the difference between diving the same spot for ten years at thirty feet and finally getting down to forty five feet where the bigger fish hold. Apnea Trainer and STAMINA are the two most widely used apps for running CO2 and O2 tolerance tables. Both walk you through standard static breath hold progressions, beep the timing for you, and track your improvement over weeks.

Breath hold tables should be done dry, on land, with a spotter or in a safe environment. Never train breath holds in water alone. Shallow water blackout is real and silent, and the divers it kills are almost always experienced, fit, and training solo.

Beyond apnea specific apps, a general fitness tracker (Garmin Connect, Apple Fitness, Strava) is useful for logging the swim and hiking fitness that actually determines how many dives you can stack in a day. A fit diver with a fifty second breath hold will outperform an unfit diver with a ninety second breath hold every time over a six hour dive day.

Dive computer companion apps

If you wear a dive computer, its companion app is the only way to unlock the data it collects. Garmin Connect pairs with the Descent series (Mk2, Mk3, G1, G2) and exports dive profiles, depth, heart rate, and GPS surface tracks, which is remarkable for breath hold review. You can see exactly where and how deep each dive was and correlate that with where you saw fish.

Suunto App is the companion for Suunto D series and modern Suunto watches, and handles freedive sessions cleanly with dive count, max depth, and session stats. Shearwater Cloud is the desktop and mobile syncing platform for Shearwater computers, widely used by technical and spearfishing crossovers.

The practical value of these apps is not the computer itself; it is the pattern that emerges over a season. Dive count per outing, average max depth, dive to surface interval ratio, and heart rate recovery are the numbers that tell you whether your conditioning is improving or whether you are coming home more tired than you need to be.

A realistic app stack for a California diver

You do not need all of these apps. A realistic working stack looks like: Windy plus NOAA Buoy Data for weather, SpearFactor Dive Conditions for dive specific forecasts, Navionics for charts and bathymetry, Fish Rules for regulations, Dive Log for logging, Tide Alert for tides, and your dive computer companion app. Everything else is a nice to have.

The diver who beats everyone else on fish to the truck is usually not the one with the newest toys. It is the one who has run the same seven apps for three years, knows what his home break looks like at a 4 foot 10 second swell versus an 8 foot 14 second swell, and has the log entries to prove which days are worth driving for.

SpearFactor Dive Conditions is free to try at conditions.spearfactor.com. It was built specifically to take the raw ocean data that the apps above serve, and turn it into a dive specific call: should I go, where, and what should I expect to see when I get wet. Load it on your phone the night before your next trip and run it alongside your regular stack. If it makes your decision easier, use it. If it does not, your feedback is what makes it better.

Image credits: Large wave breaking in Santa Cruz, California, photo by Brocken Inaglory (2009), via Wikimedia Commons (CC BY-SA 3.0). Puget Sound nautical chart, courtesy NOAA Office of Coast Survey, via Wikimedia Commons (Public Domain).