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qtVlm vs iNavX: catalog facts
qtVlm	iNavX
Screenshots	Screenshots
Best for: Cruising and racing sailors who plan routes around weather	Best for: Cruising boaters who want a handheld chartplotter on an iPhone or iPad
Free + paid options The GRIB viewer is free; mobile and tablet apps, chart packs and the GRIB service are paid.	Free + paid options Free NOAA US charts are included; other providers' charts and features may cost extra.
Windows, Android, iOS	Android, iOS
Weather routing with departure-time comparison Reads S57, S63, raster and MBTiles charts AIS and NMEA instrument support Iridium GO certified	Supports more than 25 chart providers in one app Live AIS, route planning and GRIB weather Instrument overlays for speed, heading and depth Free NOAA US charts
Mobile versions and chart packs are paid Wide feature set takes time to learn	Commercial charts from other providers are bought separately Focused on phones and tablets rather than desktop use
Downloadable app	Downloadable app
Not open source	Not open source
License not stated	License not stated
Not stated if an account is needed	Not stated if an account is needed
Not stated if it works offline	Not stated if it works offline
Official website Full listing and sources Sources for qtVlm meltemus.com apps.apple.com/us/app/qtvlm/id999110023 Catalog checked September 24, 2026	Official website Full listing and sources Sources for iNavX inavx.com Catalog checked September 23, 2026

“Not stated” means we have not confirmed it. Features can vary by device and plan.

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