ECSL · கடல் மீட்பு — மிதவைத் தேடல்

Coast-Rescue Drift-Search Field

A search ellipse expands over time around a last-known point under wind, current and leeway uncertainty.

Design study plaque · Coast-Rescue Drift-Search Field

ECSL is a public design-research surface under TLTE. No service exists. No operational authority is claimed. In an emergency call UK 999, EU 112, or the relevant Sri Lanka emergency line.

Formulae

\vec d(t) = \int_{t_0}^{t} \!\!\big( \vec u_c(\tau) + L \, \vec u_w(\tau) \big) \, d\tau

A(t) = \pi \, \sigma_x(t) \, \sigma_y(t), \;\;\; \sigma(t) = \sigma_0 + k \sqrt{t - t_0}

Variables

d⃗(t): Drift vector from last-known position
u⃗_c: Surface-current vector
u⃗_w: Wind vector
L: Leeway coefficient (vessel-dependent)
σ_x, σ_y: Search-ellipse semi-axes
k: Uncertainty growth rate (√t)

Meaning

Standard civilian Search-and-Rescue model. Used in coast-rescue training to show why early notification matters: the search area grows with the square root of elapsed time. Anchored to IMO SAR Convention 1979 and IAMSAR Manual Volume II.

Interactive sandbox

Drift-search field · σ(t) = σ₀ + k √t

elapsed hours6 hsurface current (kn)0.60 knwind (kn)8 knleeway coefficient0.035

Search area ≈ 9.7 km² · drift (6.7, 1.7) km

Sample · illustrative · 0 verified this era

Now · இரு-அடுக்கு (1)

Standard civilian SAR model (IMO 1979; IAMSAR Vol II). Used here in Coast Rescue training drafts to motivate early notification and redundant coastal stations. Never targets a real vessel.

Becoming · இரு-அடுக்கு (2)

A pedagogical surface the future Coast Rescue Service would use in school drills and harbour-safety community sessions — making the cost of late notification visible.

Anchor literature

IMO Search and Rescue Convention 1979
IAMSAR Manual Volume II · Mission Co-ordination
USCG · Leeway research (Allen & Plourde 1999)

Honest ceiling

Never targets a real vessel. No live AIS data is used here. The widget is a pedagogical surface only.

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