# CBDR — Radar & Rules of the Road > Radar and rules of the road training for maritime watchstanders. (iPhone/iPad app by Sean Bowman.) - Source: https://appshunter.io/ios/app/cbdr/id6792199258 (this page in markdown: same URL + `.md`) - Developer: [Sean Bowman](https://appshunter.io/developer/6792199260) - Category: Education, Navigation - Price: Free - Rating: 5.00/5 from 2 App Store ratings - Age rating: 4+ - Requires: iOS 17.0 · 25 MB - Languages: American English - Released: 2026-07-28 - Data updated: 2026-08-22 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/cbdr/id6792199258/reviews.md ## What is CBDR? CBDR helps to train junior deck officers in vital mariner skills. Named for constant bearing, decreasing range, the term CBDR should grab any mariner's attention, and this app is built to help develop the knowledge necessary to act IAW COLREGS while at sea, along with other mariner skills. RADAR & CONTACT REPORTS. Live scenarios on a real radar scope — north-up or course-up, relative or true vectors, trails, CPA markers. Classify the situation under the Rules, order the maneuver, and give the contact report the way it should be given. Multi-contact pictures are assessed whole, the way a bridge team has to. Speak your report and the app grades it, or type it. Every recommendation cites the Rule it stands on, and "How CBDR Decides" shows the logic in full — no black boxes. MANEUVERING BOARD. Nine Pub 1310 problem types with step-by-step worked constructions: CPA, avoidance, stationing, two-step stationing, limiting range, bearings-only TMA, fictitious ship, advance and transfer, true and desired wind. Bring your own numbers and run them through the same walkthroughs. OOD MATH. The arithmetic a watch runs on, worked in the head and on paper: minute rules (mental only — the app says so), time-speed- distance, TVMDC compass conversion, Bowditch time zones, the 60-to-1 rule staged on replenishment approaches, visibility and raising lights, doubling the angle on the bow, and anchoring — chain in whole shots, swing and drag circles in yards. RULES OF THE ROAD. The 954-question USCG bank, solo tests with immediate feedback, and every question linked to the governing Rule with the exact passage highlighted — verified verbatim against the Navigation Rules. Guided Practice learns which rules you miss and draws your sessions toward them; progress stays on your phone, and the algorithm that picks your questions is documented in the app. TIDES & CURRENTS. Station predictions for the United States and Canada, found on a map, fetched from NOAA and CHS when you ask, and kept for offline use — tables, a curve you can put your finger on, and exports for Excel and PowerPoint. Beside the lookup, teaching pages where the water moves: the reversing current run as a transit of San Diego Bay, the rotary current turning through the compass offshore, the hydraulic current in the Cape Cod Canal — and How Tides Work, the Moon's pull drawn in three dimensions, from the uneven pull and the two bulges to springs, neaps, and what the chart datum means. Every arrow and bulge is computed from the physics, and the days are honestly invented. NAVIGATION FUNDAMENTALS. Time zones with an interactive Bowditch zone map, ETA and speed-of-advance drills, and How Fixes Work — ten step-through teaching pages covering visual, radar, soundings, celestial, GPS (drawn in three dimensions, because the fourth satellite is what pins your altitude), running fix, dead reckoning, and set and drift. Never graded. They exist to teach. CHART NO. 1 ABOARD. Every symbol, abbreviation and term, reorganized by chapter and section, searchable offline, with the printed plates. CLASSROOM. Host a group exam by QR code — no server, no network. Results return by QR with per-question rubrics, and the record exports as a signable PDF roster or CSV. Everything runs offline. No account, no data collection — what you practice stays on your device, and deleting the app deletes it. Built with from experience, and checked against The American Practical Navigator, COLREGS, and Farwell's. ## Key features - Live radar scope with vectors and trails - Generated navigation scenarios - COLREGS classification - Contact report scoring - Maneuvering board drills - Recognition drills - USCG Rules of the Road test bank - Offline group testing ## Frequently asked questions about CBDR ### What is CBDR? CBDR is an educational application designed to train junior deck officers and watchstanders in core radar watch skills. It covers contact evaluation, COLREGS classification, and contact reporting through interactive simulations and drills. ### What learning methodology does CBDR use? CBDR employs a hands-on approach with a live radar scope, generated scenarios simulating various navigation situations, and specific drills for maneuvering and recognition. It also includes a comprehensive test bank for the USCG Rules of the Road. ### How does CBDR track progress? The app scores spoken or typed contact reports against correct formats, and provides results for offline group testing. This allows users and instructors to assess understanding and identify areas for improvement. ### Does CBDR offer certifications? While CBDR provides a 958-question USCG Rules of the Road test bank and offline group testing with exportable records, it does not explicitly mention offering formal certifications within the app. ### Is CBDR suitable for offline use? Yes, CBDR works entirely offline, making it ideal for training in environments with limited or no internet access. It does not require an account or collect any user data. ### What devices does CBDR support? CBDR is available on iPhone and iPad, indicated by its support for these platforms. It was last updated on August 1, 2026, with version 1.2. ### Does CBDR have ads? No, CBDR is ad-free. The application explicitly states that it contains no ads and collects no user data, ensuring an uninterrupted learning experience. ### What is the user sentiment for CBDR? Based on the available data, CBDR has a perfect 5.0-star rating from 2 reviews, suggesting a highly positive user sentiment among its current users. ## Version history (last 4 releases) ### 1.4 — 2026-08-19 NEW FEATURE - Tides & Currents • Tide & Current Lookup. Station predictions for the United States (NOAA) and Canada (CHS), found on a map, fetched on demand, and kept for offline use. Tables and a curve you can put your finger on, exports for Excel and PowerPoint, and a plain statement of when the data was fetched. This is the one feature that uses the Internet — only when you ask, sending only the area and dates you ask about, to government services, with no account and no identifier. Everything else in the app still runs entirely offline. • How Currents Work. Three teaching pages with live water: the reversing current run as a transit of San Diego Bay on its real chart geometry, the rotary current turning through the compass on an offshore rose, and the hydraulic current in the Cape Cod Canal — two real bays out of step and the head between them driving the cut. • How Tides Work. The Moon's pull drawn in three dimensions: the uneven pull, the two bulges, the Earth spinning under them while the tide curve writes itself, the three tidal patterns, springs and neaps, what the chart datum means — and a moon dial you drag around her orbit to set the sky yourself. Every arrow and every bulge is computed from the physics, not staged. ### 1.3 — 2026-08-13 Four new areas of training, and a pass over the app's own rules judgment. • Guided Practice. Rules of the Road practice that notices which rules you are weak on and draws more of them. Tracking is off until you switch it on, and the record stays on your phone. • OOD Math. The arithmetic a watch runs on: minute rules in your head, time-speed-distance, TVMDC, the 60-to-1 rule, visibility, doubling the angle on the bow, and anchoring circles. • Navigation Fundamentals. Zone time with an interactive zone map, ETA and speed of advance, and How Fixes Work — ten step-through pages covering visual, radar, soundings, celestial, GPS, running fix, DR, and set and drift. None of it is graded. • Chart No. 1 aboard. Every symbol, abbreviation and term, searchable offline, with the printed plates. • The GPS page is drawn in three dimensions, because the fourth satellite is what pins your altitude and a flat picture cannot show that. • Rules judgment: several hundred thousand generated scenarios were checked against the Rules themselves, and what that found is fixed — crossing ahead, the head-on boundary, what a report may claim about the maneuver it recommends, and which crossing pictures are dealt at all. ### 1.2 — 2026-08-01 Everything CBDR does, now organized in a central hub. • Redesigned home screen. Every mode is one tap away instead of behind a menu — live scenarios, the moboard trainer, the rules test, and group testing each have their own place. • Multi-contact contact reports. When more than one contact carries risk of collision, the report now covers all of them: full information on each, the situation you are in with each, and a single course of action reasoned over the whole picture rather than one contact at a time. • The COLREGS are now browsable. The full Navigation Rules and Annexes, searchable, offline — no longer reachable only from a quiz question. Additionally, references to COLREGS are shown for wrong answers during testing. • "How CBDR Decides" explains the app's own reasoning, step by step, so you can check its work instead of taking it on faith. • Maneuvering board: work your own numbers in "Solve My Own", now its own destination. • A new title screen, and dozens of fixes to rules judgment, report wording, and scenario generation — including a rewritten risk-of-collision model reviewed with edge cases modeled from real bridge experience. ### 1.0 — 2026-07-28 No release notes. --- *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 2026-08-22.*