Configuration

Every plugin option, set in the admin UI under Server > Plugin Config > Nemesis Delta.

Option	Meaning	Default
boats	Nemesis boats entered in advance: {mmsi, name, tcf}. See below	none
staleSeconds	A boat is stale (greyed, lines broken) after this long without a report	1800
historyHours	Track history kept in memory and on disk	120 (5 d)
recentHours	Full resolution window; older history is thinned	6
thinSeconds	One report per boat per this interval in older history	120
maxReportsPerBoat	Hard cap per boat	5000
maxBoats	Hard cap on boats tracked	500
ownSampleSeconds	Minimum interval between stored own-boat samples	1
windSmoothSeconds	Up = Upwind and Downwind: our true wind direction is a circular mean over this long	120 (2 min)
tcfVmgSeconds	TCF Should: VMG to the waypoint smoothed over this long	600 (10 min)
maxRaceHours	Ignore a start time older than this	96
waypointOrder	Next waypoint: course,nmea (Course API first) or nmea,course	course,nmea
nmeaWaypointStaleSeconds	Ignore an NMEA next point not updated for this long	30
waypointNames	Fallback waypoints (resources, by name): the first found is the waypoint when neither the Course API nor NMEA has one; each found can be picked as Up. Also the course until one is set on the Course tab	[nemesis]

Boats entered in advance (boats) are made nemeses with their TCF when they are added, and their TCF is set again when it is changed in the configuration. What was applied is remembered, so a restart (or a brownout) with the same configuration never undoes changes made in the webapp since. Removing a boat from the list leaves it as it is. A configured name is shown in this plugin instead of the name the boat sends over AIS (the snapshot's aisName keeps that, and the boat popup shows it); the Signal K data model is not changed.

The course for Up = Course is set on the webapp's Course tab and kept by the plugin (course.json in its data folder), so every screen shares it: add waypoints and move them up and down, or import a Signal K route (it replaces the course). A mark passed twice, out and back, is listed twice. Waypoint marks follow the waypoint if it is moved in the chart app; route points that are not waypoints stay where they were imported. Until a course is set there, waypointNames is the course, as in earlier versions.

The webapp's Show filter has a Sailing choice for busy harbours: it hides boats whose AIS ship type is known and is not Sailing (36), so Pleasure (37) too, boats under 0.5 kn and boats out of range, but always shows nemesis and configured boats. A boat that has not sent a ship type yet is shown.