French Guiana (France) - Suriname rhumb line instead of geodesic line

[brittlnv]

Item

Flanders Marine Institute (2023). Maritime Boundaries Geodatabase: Maritime Boundaries and Exclusive Economic Zones (200NM), version 12. Available online at https://www.marineregions.org/. https://doi.org/10.14284/632

Description

The French Guiana (France) - Suriname delimitation agreement (https://www.marineregions.org/documents/France-Suriname%20treaty.PDF) describes the boundary line as having a constant angle of 27°. It should therefore be recalculated as a rhumb line instead of a geodesic line.

[Bieniman]

In ArcGIS/ARCMAP, calculating the rhumb line using the "Sketch Tool", significantly moves it east of the current situation. The difference is very evident when compared to calculation using "Distance and Direction".

How come these methods show this big of a difference?

[brittlnv]

Our calculations are made based on the "Bearing Distance To Line" tool in ArcGIS Pro (v 3.2.0) for clarity. I have made a recalculation in ArcMap (v 10.8.2) using the Sketch Tool, but the resulting points lie about 200m to the west of the rhumb line.