Periplus

Pollica · Cilento coast real bathymetry · ISPRA meadow 06:30 wind 4 kn · sea 0.2 m
reading the seabed…
On the boat · what the crew sees
recording line 1
the bed you just passed over
good data
0
depth m
5.0
knots
calm
sea
bare
under you
Hold the line. The sounder is doing the rest.
what did you see, here?
logged, with your name on it
The student taps. The fisherman steers. Neither needs the other's job.
Plan view · coverage builds as the boat runs
depth, 0 to 120 m
Posidonia, ISPRA 2017
dead matte
not yet surveyed
2 km
Side scan · port and starboard, as it comes in
drag to turn · vertical exaggeration 8×
The job today
Progress0%
Out, across, back. The cross legs are surveyed too: they cut the offshore lines at right angles, which is what makes the profiles into a surface.
Plan the day
Nothing planned. Add a move above.
Set the net, work the meadow, be home before the front. Add the moves in the order you want them and the route follows the coast.
Steering
Speed 5.0 kn
The day
Fuel90L
Burn now3.2L/h
Fuel spent€0
Earned€0
Next jobnet 08:00
Issues reported0
Set before dawn. It has to come up inside its window or the catch is spoiled.
Conditions
Wind4kn
Sea here0.2m
Fetch upwind0.5km
Safe speed6.0kn
The breeze builds through the afternoon. Wave height comes from wind and fetch, so the lee of a headland stays workable when the open coast does not.
What you have collected
0%
area mapped
0.0
km run
0
ha meadow
0
soundings
Usable share100%
Soundings taken too fast, too deep, or in too much sea are on the map and not in the baseline.
Under the boat
Water temp0.0°C
pH8.00
Light at bed0µmol
Layers
The session
When the day ends, the run writes a survey_session/1.0: the track, every sounding with the quality it was taken at, the coverage against the shelf, and what the day cost in fuel and hours. Simulated throughout, and the file says so on every record.
The day is still running. A session is written when it ends: at 19:00, when the lines are finished, when the tank is dry, or when you call it.
Provenance
Vessel Vittorio · S. Maria
Sounder side scan, 455 kHz
Sensors temp, pH, PAR
Operator student, blue school
Bathymetry EMODnet, meadow ISPRA 2017 via EMODnet Seabed Habitats, CC BY 4.0. Sea state, light, temperature and pH are modelled.
Region pollica, from regions/.

Read a session back

Open a .session.json this tool wrote, or paste one in. It is checked against survey_session/1.0 first. If it passes, the coverage, the kept count and the spread of per-sounding quality below all come out of the file.
0
soundings
0
kept
0%
shelf mapped
0.00
mean quality
0L
fuel
0h
on the water
Per-sounding quality, ten bins from 0 to 1. A day run fast in deep water in a chop piles up on the left.