Lure Depth: Fish Color

What colour of lure can your fish actually see, at this depth, in this water? Every angler has read the chart: red dies at 5 m, chartreuse for muddy water. Those charts are drawn for one imaginary lake. Lure Depth computes the answer for YOUR water, YOUR depth and YOUR target species, from published underwater optics and measured fish physiology. And it will tell you when the honest answer is "colour is not doing any work here". WHAT YOU GET • A ranked lure table. Tell it which colours are in your tackle box and it ranks them by how much each one stands out to your target species, with an estimated distance at which the fish can detect it. • A live camera. Point your iPhone at a real lure and see it as a bass, a pike, a trout or a tuna would see it at depth. Hold anywhere to compare with the unfiltered view. It is a simulation, and it says so on screen. • 54 species, freshwater and salt: largemouth and smallmouth bass, brown and rainbow trout, northern pike, muskellunge, walleye, zander, perch, carp, catfish, Atlantic salmon, striped bass, red drum, snook, tarpon, bonefish, tuna, mahi-mahi, sailfish, marlin, swordfish and more. • 19 water types. Jerlov's oceanic and coastal optical classes for the sea, plus nine freshwater presets from gin-clear to a river in flood — tannic, blackwater, algal bloom, stained, muddy. Match yours with a Secchi reading. • Lure colours with real finish models: matte, gloss, metallic, translucent and fluorescent. THE PART NOBODY ELSE MODELS Murky water does not just block light. It glows — suspended particles scatter light back at the fish like fog lit from within, and that haze is what really kills contrast. Lure Depth models both the light going down and the haze coming back, using Duntley's contrast law. It is why the app will sometimes tell you a bright lure is invisible at two metres. THE MODEL WORKS OFFLINE No account and no server: every ranking is computed on your iPhone, so it works where there is no signal. Only purchases and the optional ad need a connection. CONDITIONS ARE ALWAYS FREE Every water type, depth, light condition and viewing angle is free and complete, permanently. Only the species catalogue is paid: one species forever with a one-time purchase, or every species with the annual Premium subscription. Four species are free forever. WHAT THIS APP DOES NOT DO It does not promise you a catch. Nothing can. It models the physics of light and contrast underwater — whether a fish can tell your lure apart from the water, which is necessary for a strike but not sufficient. It models no fish behaviour at all, and gives no advice on fishing regulations: check your local authority. THE NUMBERS ARE SOURCED Jerlov's optical water types. Pope & Fry's pure-water absorption. Duntley's contrast law. Govardovskii's visual pigment templates. Lythgoe's Ecology of Vision. Aksnes & Utne's fish visual-range model. Most fish have never had their visual pigments measured, so every species carries an evidence grade — measured, close relative, same family, or estimated — shown on the card, not buried in a footnote. SUBSCRIPTION Premium is an auto-renewing annual subscription that unlocks every species for as long as it is active. Payment is charged to your Apple Account when you confirm the purchase. It renews automatically unless cancelled at least 24 hours before the end of the current year, and you can manage or cancel it at any time in your App Store account settings. Terms of Use: https://luredepth.com/terms/ Privacy Policy: https://luredepth.com/privacy/