# tcSpeeds — Sailing Speed Instrument > Advanced sailing speed and performance instrument using device sensors. (iPhone/iPad app by transitional continuum.) - Source: https://appshunter.io/ios/app/tcspeeds/id1441225371 (this page in markdown: same URL + `.md`) - Developer: [transitional continuum](https://appshunter.io/developer/1441225370) - Category: Navigation, Sports - Price: Free with in-app purchases (on sale, was $4.99) - Rating: 4.90/5 from 10 App Store ratings · 2 written reviews indexed - Age rating: 4+ - Requires: iOS 16.6 · 18 MB - Languages: American English - Released: 2018-11-07 - Data updated: 2026-08-19 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/tcspeeds/id1441225371/reviews.md ## What is tcSpeeds? tcSpeeds provides advanced knowledge of your current speed, average speeds, maximum speed, directional speeds, velocity made good, wind measurements, and much more. You will be able to measure your performance on a straight course with our proprietary Pilot Performance Index (PPI) computation. Compare how good you are at the controls with your friends or against your autopilot. tcSpeeds stands on its own and does not require external hardware or connections to operate. tcSpeeds uses your device's own internal GPS, accelerometers, and compass. For Wind measurement, you will need to acquire the Calypso Ultrasonic Wind sensor. More sensors will be supported in the future. Easy to use and conceived to minimize operational burden on the user, because we know you have other things to do. Zero setup required: install, launch and tap the start button. Designed for iPhones, and GPS-equipped iPads. CAPABILITIES - Add waypoints on the map - Apple watch extension - auto-VMG Velocity Made Good automatic detection - Add, move, or edit you waypoint location on the map - Cross track to waypoint indicator - Record and save your track - Start Line guide for speed and heading when you race - VMG automatic maximum VMG to waypoint - VMG visual assistant: guides you to the best course to the waypoint on the current tack - Maximum VMG indicator relative to waypoint - Audio alert for Acceleration and maximum speed: get instant feedback for you and your team when you are doing it right - Apple Watch Extension: Speed, Course, VMG, Cross-Track, Display remote control and more - Arrival Time: smart computation using filtered VMG averages - Barometer indicator on supported devices - Pilot Performance Index (PPI) calculation improvement - Speed indicator with color-scaled plot - Directional speed vectors panel with automatic polar graph - Maximum speed keeping - Maximum speed audio and visual alarms - Trip distance recording - Add, move, edit Waypoints - Accurate sub-second timer - GPS status with location accuracy indication - Boxed average speed by timed interval: 10-sec 1-min 10-min 1-hour - Pilot Performance Index (PPI) calculation, measurement, and guide - Target course indicator with automatic and manual fine tuning - Headings, bearings and directional indicators (magnetic/true) - Precise real-time cross track reporting - Course, Compass and proprietary C-Course heading selector - Rapid units selection: metric, nautical and imperial - Situational (non-navigational) map with color-coded speed track - Map display with target course and Look-Ahead-Vector (LAV) - Time and distance to autoscaled LAV endpoint - Velocity Made Good (VMG) relative to Waypoint - Magnetic compass and Course Over Ground (COG) integrated panel - Crab angle and local magnetic declination ## Key features - Advanced speed and velocity measurements - Proprietary Pilot Performance Index (PPI) - Wind measurement with optional sensor - Waypoint navigation and tracking - Apple Watch extension - Real-time performance alerts ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Advanced Performance Features | $2.99 | one-time | ## Recent user reviews (2 of 2) All indexed reviews: https://appshunter.io/ios/app/tcspeeds/id1441225371/reviews.md ### 5/5 — Fun to use! *2018-12-15* Lots of unique features. I love the Vectors page and Max speed audio alarm. Great companion to my chartplotter! ### 4/5 — Update- Tc generously corrected the problem . *2018-12-05* A week ago I paid $6.99 for this app now it is free and you have to buy features. These should be free to current owners! **Developer response:** Hi AceArnie, Sorry about that. This is my first app and I did not know how to proceed with this pricing change. I agree with you. Please send me an email at support@transitionalcontinuum.com and we can arrange that. -Tomas ## Frequently asked questions about tcSpeeds ### What devices does tcSpeeds support? tcSpeeds is designed for iPhones and GPS-equipped iPads. It also features an Apple Watch extension for convenient access to key metrics and remote control. ### Does tcSpeeds require external hardware? No, tcSpeeds stands on its own and uses your device's internal GPS, accelerometers, and compass. For wind measurements, an external Calypso Ultrasonic Wind sensor is required. ### How easy is tcSpeeds to set up? tcSpeeds is designed for minimal operational burden. Zero setup is required; simply install, launch, and tap the start button. ### What kind of performance data does tcSpeeds provide? It offers current speed, average speeds, maximum speed, directional speeds, velocity made good (VMG), wind measurements, and a Pilot Performance Index (PPI). ### Can I compare my performance with others using tcSpeeds? Yes, you can compare your performance metrics, including your Pilot Performance Index (PPI), with friends or against your autopilot. ### What is the Pilot Performance Index (PPI)? The Pilot Performance Index (PPI) is a proprietary computation that measures your performance on a straight course, allowing you to gauge your skill at the controls. ### How often is tcSpeeds updated? The latest version is 3.4, last updated on March 25, 2026. Future updates are planned to support more sensors. ### What is the age rating for tcSpeeds? tcSpeeds has an age rating of 4+, making it suitable for a wide range of users. ## Version history (last 5 releases) ### 3.4 — 2026-03-25 v3.4 — Wind & Watch upgrade • Apple Watch: True Wind Speed (TWS) now shown on Wind Compass in yellow, Apparent Wind Speed (AWS) in green — both with color-coded direction triangles • Watch speed display fills the full Apple Watch Ultra screen with a cleaner layout • Watch complication now shows the tcSpeeds icon on your watch face • All watch numbers grey out when iPhone connection is lost • Map GPS track color coding fixed — no more disappearing track on zoom/pan • Connect to Calypso wind sensor now requires purchase (as intended) ### 3.0 — 2022-11-05 - Wireless wind sensor data: Calypso Ultrasonic - https://calypsoinstruments.com/shop/product/ultrasonic-portable-solar-wind-meter-2 - Track logging and recording - Multiple waypoints support - Start line guide when you race - Updated user experience - Updated Apple Watch extension - And much more ### 2.1 — 2021-06-21 Version 2.1 - Minor bug fixes - User Interface improvements - Performance improvements - Stability improvements ### 2.0 — 2021-01-24 Version 2.0: NEW FEATURES - NEW: Add a waypoint on the map - NEW: Apple watch extension - NEW: autoVMG - Velocity Made Good automatic detection - Add, move, or edit you waypoint location on the map - Cross track to waypoint indicator - autoVMG automatic maximum VMG to waypoint - autoVMG visual assistant: guides you to the best course to the waypoint on the current tack - Maximum VMG indicator relative to waypoint - Audio alert for Acceleration and maximum speed: get instant feedback for you and your team when you are doing it right - Apple Watch Extension: Speed, Course, VMG, Cross-Track, Display remote control and more - Arrival Time: smart computation using filtered VMG averages - Barometer indicator on supported devices - Pilot Performance Index (PPI) calculation improvement - Runs on iOS 9.3 or later (it should run on an old iPad: cellular models only). - Stability improvements - And so much more! Please provide feedback or suggest updates: support@transitionalcontinuum.com Visit my website: transitionalcontinuum.com tcSpeeds demonstration video: https://youtu.be/gLq6fn7qPWE Developed and tested offshore by Tomas Ryan ### 1.3 — 2020-06-19 NEW FEATURES: - Timer start can be set to negative time values - Improved speed filter - Improved distance filter - Stability improvements - Various minor improvements - Apple Watch extension - WITH KNOWN BUG: tcSpeeds data communication sometimes stops temporarily. I will try to fix that in the next version. Let me know what you think. I am open to suggestions. If you do not like tcSpeeds, please tell me why so I can make improvements. Email me at support@transitionalcontinuum.com Visit us at transitionalcontinuum.com -Tomas ## Apps similar to tcSpeeds | App | Rating | Price | Category | | --- | --- | --- | --- | | [iEFIS Pro](https://appshunter.io/ios/app/iefis-pro/id1217787841) | 5.0 (2) | Free | Navigation | | [GPS-Speedometer](https://appshunter.io/ios/app/gps-speedometer/id339748125) | 2.0 (1) | $2.49 | Navigation | | [GPSlogger Kalman](https://appshunter.io/ios/app/gpslogger-kalman/id1521553554) | — | $3.99 | Navigation | | [WatchVario](https://appshunter.io/ios/app/watchvario/id1668552156) | — | $0.99 | Navigation | | [SpeedGPS - Drive & Measure](https://appshunter.io/ios/app/speedgps-drive-and-measure/id6479700883) | 5.0 (2) | Free | Navigation | | [Dashcam - Car Crash Recorder](https://appshunter.io/ios/app/dashcam-car-crash-recorder/id1212010830) | 4.1 (228) | Free | Navigation | --- *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 2026-08-19.*