Port Starboard Signed Offset Crosswalk Tool

Description

Return the absolute offset as magnitude and infer port or starboard from its sign and positiveStarboard.

Port and starboard are vessel-relative directions. A transverse coordinate's sign depends on which side the source convention calls positive.

Return the absolute offset as magnitude and infer port or starboard from its sign and positiveStarboard.

Use Port Starboard Signed Offset Crosswalk when you need to translate a stated vessel transverse sign convention.

Enter offset, positiveStarboard. Use the units and conventions below.
Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
Read side, magnitude. Use the output convention below.

Return the absolute offset as magnitude and infer port or starboard from its sign and positiveStarboard. Label zero center.^[1]

Input field	Meaning and units	Accepted input
offset	Offset	Required. Finite number.
positiveStarboard	Positive Starboard	Required. Boolean.

Output field	Interpretation	Returned shape
side	Side	Required. Text; maximum UTF-16 length 8192.
magnitude	Magnitude	Required. Finite number.

json

{
  "input": {
    "offset": -3,
    "positiveStarboard": true
  },
  "output": {
    "side": "port",
    "magnitude": 3
  }
}

This translates a sign convention only; no vessel position or clearance is checked.
Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Preserve the source coordinate frame and use a full spatial transformation when heading or global position is involved.

Ship Frame Port Starboard Sign
Retain or negate transverseCoordinate to obtain a starboard-positive value.
Nautical: Vessel Port Star Board Coordinate Sign
Convert transverseCoordinate to a starboard-positive coordinate by retaining or negating it according to positiveSide.