# Thalos — Professional Dive Tools > All-in-one offline dive log, planning, and instructor tools for serious divers. (iPhone/iPad app by JOHN WALLIS YOUNGBLOOD.) - Source: https://appshunter.io/ios/app/thalos/id6761337227 (this page in markdown: same URL + `.md`) - Developer: [JOHN WALLIS YOUNGBLOOD](https://appshunter.io/developer/1888980268) - Category: Sports, Education - Price: Free with in-app purchases - Rating: 5.00/5 from 1 App Store ratings - Age rating: 4+ - Requires: iOS 15.1 · 41 MB - Languages: English - Released: 2026-04-08 - Data updated: 2026-06-26 - Monetization: subscription - User reviews in markdown: https://appshunter.io/ios/app/thalos/id6761337227/reviews.md ## What is Thalos? Thalos is the all-in-one dive app built for serious divers and instructors. Whether you're planning a deep technical dive or running an open water course, Thalos has everything you need — and it works fully offline when it matters most. DIVE LOGBOOK Log every dive with depth, time, gas, conditions, marine life sightings, buddy signatures, and photos. Full version history keeps your records safe. Organize dives into trips and track your personal certifications. DIVE SITES & EMERGENCY PLANS Access 510+ dive sites with detailed emergency action plans, nearest hyperbaric chambers, and emergency contacts — all stored locally so they're available even without signal. 9 DIVE CALCULATORS • Bühlmann ZHL-16C decompression planner with gradient factors • Gas planner and gas blending • SAC rate, turn pressure, weight calculator • Dive tables, unit converter, altitude diving EMERGENCY MODE One tap gets you to emergency procedures and critical contacts. Works 100% offline. INSTRUCTOR MODULE Manage students, run courses with 26 built-in templates, track skill sign-offs, generate paperwork (liability waivers, medical forms, training dives), and issue certifications. SOCIAL FEED & TANK TAPS Share your dives, follow other divers, and give Tank Taps — the diver's way of saying nice dive. COMMUNITY Discover and post dive classes, trips, and dive centers. Instructors can manage enrollments directly in the app. SUBSCRIPTION Thalos requires a subscription after a 1-month free trial. $2.99/month or $19.99/year. Terms of Use: https://blackflagdivecenter.github.io/Thalos/terms.html Privacy Policy: https://blackflagdivecenter.github.io/Thalos/privacy.html ## Key features - Offline dive logbook - Dive site database with emergency plans - 9 essential dive calculators - Instructor module for course management - Social feed and community features - Emergency mode for critical access ## Pricing and in-app purchases Base price: Free. **Subscriptions** | Subscription | Price | Period | | --- | --- | --- | | Thalos | $2.99 | per month | | Thalos | $19.99 | per year | ## Frequently asked questions about Thalos ### What is Thalos? Thalos is a comprehensive dive application designed for serious divers and instructors. It offers features like a dive logbook, dive site information with emergency plans, and various dive calculators, all of which can be used offline. ### Does Thalos work offline? Yes, Thalos is designed to work fully offline. This ensures that critical data such as your dive logbook, dive site information, emergency plans, and calculators are accessible even without an internet signal. ### What dive calculators are included in Thalos? Thalos includes 9 dive calculators, such as a Bühlmann ZHL-16C decompression planner with gradient factors, a gas planner and gas blending tool, SAC rate calculator, turn pressure calculator, weight calculator, dive tables, unit converter, and altitude diving calculator. ### Can instructors use Thalos? Yes, Thalos features an instructor module. This allows instructors to manage students, run courses using 26 built-in templates, track skill sign-offs, generate paperwork, and issue certifications. ### How much does Thalos cost? Thalos requires a subscription after a 1-month free trial. The subscription costs $2.99 per month or $19.99 per year. ### What devices does Thalos support? Based on the provided data, Thalos supports iPhones and iPods. It is rated for ages 4 and up. ### How often is Thalos updated? The latest version of Thalos is 1.3.8, and it was last updated on June 20, 2026. This suggests a relatively active update schedule. ### Does Thalos have ads? No, Thalos does not contain advertisements. The app is free to download and offers a subscription for full access to its features. ## Version history (last 5 releases) ### 1.3.8 — 2026-06-20 Build fixes and additional features ### 1.3.5 — 2026-05-07 Bug Fixes and new dive package calculator ### 1.0.4 — 2026-04-13 Bug Fixes and Profile Pictures ### 1.0.3 — 2026-04-12 Bug Fixes ### 1.0.2 — 2026-04-11 Bug Fixes --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-26.*