DRFT MRKS vs Roll Period
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
DRFT MRKS
This application uses AI and deep learning to accurately measure a vessel's draft from a short HD video. It aims to provide a verifiable source of truth for calculating vessel displacement, improving accuracy in determining loaded cargo and equipment.
- AI/Deep Learning technology
- Measures vessel draft from video
- Improves draft reading accuracy
- Verifiable source of truth
- Calculates vessel displacement
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Tymor Marine's breakthrough DRFT MRKS technology measures a vessel's draft from a 30-second, 1080p HD video. It is an industry-leading AI/Deep Learning technology developed to improve the traditional draft reading process. DRFT MRKS aims to allow anyone to read draft marks with the same skill and accuracy as an experienced mariner. Discrepancies can lead to incorrect displacement measurements, spark disputes over cargo quantities, and impose operational limitations on vessels. DRFT MRKS provides a single verifiable source of truth when calculating vessel displacement using draft marks, helping to improve accuracy when determining loaded cargo/equipment.
Roll Period
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RollPeriod transforms your smartphone into a practical tool for vessel motion analysis. Using the built-in accelerometer, the app provides real-time measurements and insights: Roll and pitch periods are calculated with FFT analysis. Data import and export with CSV file support. Whether you are a sailor, marine engineer, or navigation enthusiast, RollPeriod helps you better understand vessel dynamics and make safer decisions at sea.
Screenshots
Verdict
The clearest difference is update cadence: DRFT MRKS at monthly against Roll Period's every 13 months. Roll Period's advantage is iOS requirement (15.0 vs 18.0). On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
DRFT MRKS ships an update monthly, Roll Period every 13 months. The most recent releases landed on November 4, 2026 and October 30, 2026 respectively.
| Parameter | DRFT MRKS | Roll Period |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | — |
| Number of ratings | 1 — better | — |
| Update frequency | Monthly — better | Every 13 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone | iPhone, iPod — better |
| Requires iOS | 18.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 60 MB | 27 MB |
| Age rating | 4+ | 4+ |
| Developer | Tymor Marine Ltd | Rob Grin |
In-app purchases
DRFT MRKS
No in-app purchases
Roll Period
No in-app purchases
