Abstract:
This study aims to analyze the effectiveness of Standard Marine Communication Phrases
(SMCP)-based radio communication between the Sunda Strait VTS operators and the
ship officers of the watch (commercial and ferry), as well as to evaluate the coordination
patterns and surveillance mechanisms of VTS regarding Non-Compliance with the
Mandatory Reporting System (MRS) in preventing ship collision risks in narrow fairways
and the Sunda Strait Traffic Separation Scheme (TSS). The research methodology used is
descriptive qualitative with a case study approach. Data were gathered through In-depth
Interviews with six informants (three VTS operators and three officers of the watch),
direct Observation in the Sunda Strait VTS Control Room, and the analysis of operational
documents (VHF communication logbooks, AIS track recordings, and VTS SOPs). Source
and method triangulation were applied to ensure the credibility of the findings. The
results indicate that the effectiveness of radio communication fluctuates: under routine
conditions, compliance with SMCP and Closed-loop Communication reaches 75–85%,
but during peak hours in the TSS, it drops to approximately 60%, with the execution of
Read-Backs plunging below 40%. Most vessels only respond to VTS instructions with
"Roger" or "Copy" without repeating maneuvering parameters, creating an "illusion of
communication" that shortens the Time to Closest Point of Approach (TCPA) and
increases the risk of incidents. Regarding MRS compliance, the rates vary: Sailing Plan
~85%, Position Report ~65%, and Deviation Report is critically low (~40%), causing
Blind Spots in the VTS Traffic Image and forcing a shift in the surveillance mechanism
from preventive to reactive through Proactive Calling. This study recommends four
problem-solving alternatives: (1) strict enforcement of a Closed-loop Communication
protocol, (2) digitalization of the MRS based on AIS-integrated e-reporting, (3) scenario-
based VTS-ship training simulations specific to the Sunda Strait, and (4) strengthening
SOPs through post-operational Feedback Loops. The combination of Alternatives 1 and
4 is determined to be the most viable short-term solution, while Alternatives 2 and 3 serve
as systemic mid-to-long-term reforms.
