UKC Planner

INPUT DATA

Vessel & Passage

Vessel particulars

LBP m Beam m Draft forward m Draft aft m Displacement t Cb override optional

Waterway & motion

Charted depth m Current tide height m above chart datum Speed through water kn Water density t/m³ Channel width m; 0 = Barrass width FWA mm

Squat model Method

Dynamic allowances

Heel angle deg Heel allowance override m Wave allowance m Manual draft correction m CATZOC Extra survey allowance m Other allowance m

Required UKC policy

Minimum UKC m Minimum UKC % of adjusted draft Additional company margin m

Uses the greater of the fixed requirement and the percentage-of-draft requirement, then adds the company margin.

Bridge / overhead clearance

Include bridge constraint Charted vertical clearance m Charted-clearance reference tide m above same datum Vessel air draft m, waterline to highest point Vertical motion allowance m Bridge / vertical survey allowance m Required air-clearance margin m Credit vessel squat

Current bridge clearance = charted vertical clearance + reference tide − current tide. If the charted clearance is referenced to HAT, enter HAT as the reference tide. Use the same vertical datum for both tide values.

CURRENT CONDITION

Clearance Status

—

AVAILABLE DYNAMIC UKC—m

UKC MARGIN—m

AIR-CLEARANCE MARGIN—m

UKC—

BRIDGE—

SPEED ADVISOR

Maximum speed under enabled clearance constraints

—kn

Block coefficient Cb—

Width of influence—

Effective channel width—

Blockage factor—

VISUAL CLEARANCE

Under-Keel Clearance

OVERHEAD CLEARANCE

Bridge / Charted Height

—

SENSITIVITY ANALYSIS

Speed Curves

Max speed kn

Squat vs speed

Dynamic UKC vs speed

TIDAL WINDOW PLANNER

UKC + Bridge Passage Window

SAFE WINDOWS0

Window start Duration hours Calculation step minutes Speed ceiling scan kn

Prediction eventsUse official HW/LW predictions. Interpolation is a smooth planning approximation between entered extrema.

LW 1m

HW 1m

LW 2m

HW 2m

Combined constraint: a time is marked safe only when dynamic UKC and the enabled bridge air-clearance requirement are both satisfied at the current passage speed.

SQUAT MATRIX

Depth × Speed Table

meets UKC requirement below requirement

WHAT-IF ANALYSIS

Scenario Comparison

TRANSPARENT CALCULATION