# TVMDC Sailing & Marine Navigation Calculator > Marine navigation calculator for TVMDC, set/drift, and course to steer. (iPhone/iPad app by peter hopper.) - Source: https://appshunter.io/ios/app/tvmdc-sailing-and-marine-navigation-calculator/id981722780 (this page in markdown: same URL + `.md`) - Developer: [peter hopper](https://appshunter.io/developer/981722779) - Category: Navigation, Education - Price: $4.99 - Rating: 3.00/5 from 2 App Store ratings · 3 written reviews indexed - Age rating: 4+ - Requires: iOS 8.2 · 13 MB - Languages: American English - Released: 2015-04-09 - Data updated: 2026-08-29 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/tvmdc-sailing-and-marine-navigation-calculator/id981722780/reviews.md ## What is TVMDC Sailing & Marine Navigation Calculator? A Simple to Use, Marine Navigation Calculator App - for Sailors and Navigators learning to use Charts. The TVMDC App performs three functions: - * Instant TVMDC corrections between True, Magnetic and Compass bearings. * Set & Drift Calculations from two known Fixes. * Calculation of "Course to Steer" (CTS) based upon a Destination while factoring in both TVMDC and 'Set & Drift' corrections. Allows you to move between True, Magnetic and Compass bearings instantly. A True, Variation, Magnetic, Deviation, Compass (TVMDC) Calculator. Ideal for Sailors who are learning to Navigate with Charts. Includes corrections for : Variation, Annual Magnetic Variation Drift, a boat's Deviation, Set and Drift factors. Simple to use: Input values form the your nearest Chart's Compass Rose: including Variation and Annual Increase. Along with your boat Compass's Deviation. The Calculator will instantly correct between any: True, Magnetic and Compass bearings. Add two known fixes along with your boat's Heading and Speed through the Water. Press Calculate and the App will display your calculated "Set and Drift" values along with a graphical sailing triangle. Any heading or bearing is adjusted for Magnetic Variation and Deviation. Add your Destination and the Calculator will provide your best Course to Steer: factoring in TVMDC and Set and Drift errors. American Sailing Association (ASA) course 105 (Navigation) is an ideal back ground for the App. Also, wikipedia's TVMDC description : http://en.wikipedia.org/wiki/TVMDC YouTube TVMDC App Introduction tutorial: https://www.youtube.com/watch?v=u4d5wCgPxwg Extensive Help at: http://www.arintoapps.com Runs on iPhones 5, 6 and 6+, 7, 7+ in Portrait mode ONLY. Planning on new versions and extensions; so please feedback feature requests? ## Key features - TVMDC corrections (True, Magnetic, Compass) - Set & Drift calculations from two fixes - Course to Steer (CTS) calculation - Variation and Deviation corrections - Graphical sailing triangle ## Recent user reviews (3 of 3) All indexed reviews: https://appshunter.io/ios/app/tvmdc-sailing-and-marine-navigation-calculator/id981722780/reviews.md ### 4/5 — Very nearly 5 Stars. Recommended. *2019-01-08* Useful app. Could be improved further of coordinates could be entered in format Degrees Decimal Minutes as opposed to just DMS. ### 5/5 — Great training app for boaters and cruisers *2017-06-30* This app is exceptional tool for honing your boating skills while not on the water (like those cold winters up north). Safe boating and piloting courses can really take advantage of this app. ### 5/5 — Suggestions! *2016-05-29* Many tanx for your good program. As a marine officer inform you, mostly we need a program for gyro error. Final calculate DEVIATION. If mention this part your program will be tje best. ## Frequently asked questions about TVMDC Sailing & Marine Navigation Calculator ### What is the TVMDC app? The TVMDC app is a marine navigation calculator designed for sailors. It helps users perform instant TVMDC corrections between True, Magnetic, and Compass bearings, calculate Set & Drift from two known fixes, and determine the 'Course to Steer' based on a destination. ### What corrections does the TVMDC app include? The TVMDC app includes corrections for Magnetic Variation, Annual Magnetic Variation Drift, a boat's Deviation, and Set and Drift factors. It allows for instant correction between True, Magnetic, and Compass bearings. ### How does the TVMDC app calculate Set & Drift? To calculate Set & Drift, you input two known fixes along with your boat's Heading and Speed through the Water. The app then displays the calculated 'Set and Drift' values and a graphical sailing triangle. ### What is the price of the TVMDC app? The TVMDC app is available for a one-time purchase price of $4.99. ### What devices is the TVMDC app compatible with? The TVMDC app runs on iPhones 5, 6, and 6+, 7, and 7+ in Portrait mode only. It is also supported on iPods. ### How often is the TVMDC app updated? The TVMDC app was last updated on January 18, 2017, with version 4.0. The developer is planning new versions and extensions and welcomes feature requests. ### What is the user rating for the TVMDC app? The TVMDC app has a rating of 3.0 stars based on 2 user ratings. ### Does the TVMDC app have ads? No, the TVMDC app does not contain advertisements. It is a paid application without any in-app purchases or ads. ## Version history (last 4 releases) ### 4.0 — 2017-01-18 This update from Apple will improve the functionality of this app. No new features are included. Improved usability with new dynamic color of Calculate button to help user understand when inputs have changed or not. Improved textfield inputs now do not require user to hit return to input values. Updated for iOS 10.x Minor bug fixes. ### 3.0 — 2016-02-10 Minor Fixes and changes to Docs.. ### 2.0 — 2015-09-22 Added Set & Drift Calculations with Set & Drift calculator Triangle. Added Course to Steer calculations and a CTS Sailing Triangle. Added Settings to store your current location Quadrant on the planet. Added Settings to store preferred labels on Sailing triangles. Add Longitudinal Correction factor for high attitude Sailing. Minor bugs fixes for TVMDC module. ### 1.0 — 2015-04-09 No release notes. ## Apps similar to TVMDC Sailing & Marine Navigation Calculator | App | Rating | Price | Category | | --- | --- | --- | --- | | [Waterway Guide](https://appshunter.io/ios/app/waterway-guide/id1551794976) | 4.7 (2,877) | Free | Navigation | | [ACR Product App](https://appshunter.io/ios/app/acr-product-app/id1458864580) | 1.5 (31) | Free | Navigation | | [TZ iBoat – Marine Navigation](https://appshunter.io/ios/app/tz-iboat-marine-navigation/id1312769833) | 4.7 (871) | Free | Navigation | | [C-MAP: Boating](https://appshunter.io/ios/app/c-map-boating/id967289980) | 4.5 (2,347) | Free | Navigation | | [Aqua Map Boating](https://appshunter.io/ios/app/aqua-map-boating/id919552329) | 4.7 (13,587) | Free | Navigation | | [iNavX: Marine Navigation](https://appshunter.io/ios/app/inavx-marine-navigation/id286616280) | 4.8 (21,564) | Free | Navigation | ## More apps by peter hopper - [Curtain Calculator](https://appshunter.io/ios/app/curtain-calculator/id1067733929) - [EVHotels](https://appshunter.io/ios/app/evhotels/id1343918730) All apps by peter hopper: https://appshunter.io/developer/981722779 --- *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 2026-08-29.*