~/challenges $ cat weekly/05_ghost_in_the_ballast.md
Data Analysis Difficulty: Medium
Live · Week 05
CHALLENGE #05 · Released 5 May 2026

Ghost in the Ballast

REWARD +250 pts

Briefing

intel://sss/briefing_05.txt

INTELBergen, 11:14 local. The MV Saltstrøm, a Vestmar Shipping AS chemical tanker, is heeling across the Skagerrak. The bridge data says it isn’t. Pumps nominal. Valves nominal. No alarm. A manual sounding finds Tank B visibly lower than the automation reports.

Vestmar has forwarded the ballast telemetry to the Security Special Services Team. Every reading within tolerance. Every reading lying.

This carries Solstice Prime’s signature. Operator, can you find what they hid?

Objective

Something is hiding in the Tank B readings — find it and submit your flag.

Evidence

.csv
saltstrom_ballast_2026-04-28.csv
csv
↓ Download

Capture the Flag

Submit your solution · +250 pts on success
Format: GRID-2026-XXXX
One submission per solve. Points post to the leaderboard on verify.