Route Analysis and Export
You've calculated a route. Now examine it critically — the logbook, histogram, and statistics views show you what the router is actually proposing before you commit to sailing it.
The Route Logbook
The Route Logbook is your primary tool for understanding what the router is actually proposing. Access it through Routes → Edit Route (select your route first) or by right-clicking the route and selecting Logbook. It shows a table of every waypoint along the route with the predicted conditions at each point.
Each row in the logbook represents a waypoint or time step along the route. The columns show: UTC time, position (lat/lon), heading (course to steer), distance to next waypoint, TWS (true wind speed), TWD (true wind direction), TWA (true wind angle — your point of sail), boat speed, and cumulative distance. This is the route broken down into navigable segments.
Read the logbook like a watch schedule. Step through the entries and ask yourself: Would I be comfortable sailing these conditions at this time of day? A logbook entry showing 28 knots TWS at 0300 UTC with TWA 45° means a hard beat in near-gale conditions in the middle of the night. The route might be fastest, but is it something your crew can handle?
You can configure which parameters appear in the logbook and at what intervals. For a 5-day passage, 6-hour intervals give you a manageable overview. For a 24-hour coastal passage, 1-hour intervals show the evolution in detail. The logbook is also the best tool for briefing crew — print it or screenshot it and everyone knows what to expect.
Before accepting any route, read the logbook entries for the nighttime hours specifically. Rough conditions during the day are manageable; the same conditions at 0300 with a tired crew are a different proposition. If the worst conditions fall at night, consider adjusting your departure time.
What does TWA in the route logbook tell you?
Histogram and Statistics
The Histogram view displays route conditions as a time-based graph rather than a table. Access it through the route analysis tools. The horizontal axis is time (from departure to arrival), and the vertical axis shows wind speed, wave height, boat speed, or other parameters. This visual format makes it instantly obvious where the hard parts are — spikes in wind speed, drops in boat speed, transitions between points of sail.
Look for patterns in the histogram. A smooth, gradually changing wind speed line suggests stable conditions — the router has found a weather window. A line with sharp spikes means the route passes through wind transitions or frontal systems. A boat speed line that drops to zero or near-zero identifies calm zones where you'd be motoring. Each of these patterns informs your decision about whether to accept the route or adjust parameters.
The Statistics summary provides aggregate numbers for the entire route: total distance, estimated duration, average boat speed, maximum wind speed encountered, maximum wave height, percentage of time spent beating/reaching/running, and percentage of time motoring. These headline numbers let you compare routes quickly — Route A is 12 hours shorter but has 8 hours of beating; Route B adds a day but is all reaching.
Use statistics to compare multiple departure times. Run the same route for 3-4 departure times (e.g., every 12 hours over 2 days) and compare the statistics. Often one departure time is dramatically better — shorter duration, lower maximum wind, less beating — because it catches a weather window that the other departures miss.
When comparing departure times, pay more attention to maximum wind and wave conditions than to total duration. A route that's 6 hours longer but keeps maximum wind under 20 knots is often preferable to a faster route that puts you in 30 knots — especially with a tired or inexperienced crew.
What is the best use of the route statistics summary?
GPX Export and Chartplotter Transfer
Once you've analyzed and accepted a route, the next step is often exporting it for use on your chartplotter, tablet navigation app, or for sharing with crew. qtVlm exports routes as GPX files — the universal standard that every navigation device and app can import.
Export through Routes → Export Route → GPX. The exported file contains the route waypoints with names, positions, and the sequence. It doesn't contain the weather data or timing — just the geographic waypoints. This is normal and expected; the chartplotter will display the route as a series of waypoints and legs that you navigate conventionally.
To transfer to a chartplotter, copy the GPX file to a USB drive or SD card and import it on the plotter. Most modern plotters (Garmin, Raymarine, B&G, Furuno) have a GPX import function in their route management menu. The waypoints appear as a route you can activate and navigate. For tablet apps (Navionics, iSailor, OpenCPN), share the GPX file via email, cloud storage, or direct file transfer.
Consider exporting a simplified version of the route for the chartplotter. A route with 50 waypoints is hard to manage on a plotter; one with 8-10 waypoints is much more practical. Use qtVlm's Maximum simplification to reduce waypoints before exporting. You can always refer back to the detailed version in qtVlm if needed.
Export two versions: a simplified route (8-10 waypoints) for the chartplotter, and the full detailed route as a backup reference. The simplified version is what you'll actually navigate; the detailed version shows the original routing intent if you need to re-evaluate mid-passage.
What data does a GPX export contain?
Printing and Sharing Route Plans
Even in the digital age, a printed route plan is valuable seamanship. It serves as a backup if electronics fail, a briefing document for crew, and a reference that doesn't require navigating software menus while the boat is bouncing around.
qtVlm doesn't have a dedicated print function, but the logbook and statistics views can be screenshotted or copied to create a route document. A practical route plan includes: a chart screenshot showing the route with waypoints labeled, the logbook table showing conditions at each waypoint, the statistics summary, and any notes about constraints (why certain Pathways or Boundaries were set). Format this as a single page or two and print it.
Share route plans with crew before departure. Everyone aboard should know the planned route, expected conditions, key waypoints, and decision points (e.g., 'if winds exceed 30 knots at waypoint 4, we divert to the bolt-hole at waypoint 3'). The route plan becomes part of your passage briefing alongside safety procedures, watch schedules, and emergency plans.
For remote sharing (with a shore-based weather router or a fleet sailing together), export the GPX file and the logbook screenshot. The GPX file lets the recipient load the route in their own navigation software; the logbook provides context about expected conditions. Many rally and fleet organizers use this workflow to coordinate departures.
Include decision points on your printed route plan: 'At waypoint 5, if actual wind >25kts, divert to alternate waypoint 5A.' Pre-planning these decisions ashore, when thinking is clear, is far easier than making them at 0200 in deteriorating conditions.
Why is a printed route plan still valuable alongside electronic navigation?
Summary
The Route Logbook shows waypoint-by-waypoint conditions — read it like a watch schedule to evaluate comfort and safety, especially during nighttime hours.
The Histogram view displays wind and boat speed as time graphs — spikes and drops reveal challenging sections at a glance.
Route Statistics provide headline numbers (duration, max wind, beating percentage) for quickly comparing routes and departure times.
Export routes as GPX files for chartplotters and navigation apps — export a simplified version (8-10 waypoints) for practical on-board navigation.
Print a route plan with chart, logbook, statistics, and decision points as a crew briefing document and electronics-failure backup.
Key Terms
- Route Logbook
- A table showing predicted conditions at each waypoint along the route — time, position, heading, wind speed, wind angle, and boat speed
- Histogram
- A time-based graph of route conditions showing wind speed, wave height, or boat speed over the passage duration
- Statistics
- Aggregate route numbers — total distance, duration, average speed, max wind, percentage of beating/reaching/running
- GPX
- GPS Exchange Format — the universal standard for exporting waypoints and routes to chartplotters and navigation apps
- Route plan
- A printed or shared document containing the route chart, logbook, statistics, and decision points for crew briefing and backup navigation