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To support and facilitate deep-water operations, accurate measurements of metocean conditions are needed to assess constraints and provide criteria for offshore design and installation. BHP Billiton installed three deep-water (1,770 – 2,120m), taut-line moorings for 12-months in 2014-2015, offshore Trinidad and Tobago measuring waves, currents, salinity, and temperature to accomplish this task. An associated metocean analysis was performed on the Acoustic Wave And Current (AWAC) sensor data, with supporting Navy Global Environmental Model wind data. The objective of this study was to analyze the AWAC data to understand the wave climate in the region, and specifically, to perform a wave partitioning analysis to compute time-evolving wind-sea and swell wave system parameters. The data set was then used to check analyses and predictions made in the development of operational and extreme metocean design and operational criteria. Taut-line moorings can periodically respond to forcing, dependant on mooring length, mass, buoyancy and drag, which can negatively influence measured directional wave characteristics. Analysis found that the natural mooring response frequency to periodic forcing was in the range of 140 s, outside the range of wave or current variability in the region. Wind roses verify the predominance of easterly wind flow with corresponding waves roughly aligned. Bulk significant wave heights appear normally distributed with a median wave height of approximately 1.4 m. Peak periods are predominately 8-9 s, with occasional wave events to approximately 18 s period. Wave directions are east-northeast to east most commonly, and most energetic during winter and spring. There is an absence of waves from the south and west due to the blocking effects of Trinidad and South America. Peak wave events were identified with a peaks-over-threshold algorithm, for Hs > 1.5 sigma above the mean, showing a maximum event with Hs = 4.0 m and Tp = 10.6 s, and three events with Tp > 13 s at all 3 moorings with directions mostly from the northeast. Wave spectra directional distributions at higher frequencies appeared compromised as a result of instrument deployment depths, affecting the horizontal spacing of near surface velocity cells used in internal AWAC processing. Modified spectral partitioning with high-frequency masking was developed to eliminate suspect frequencies from the analysis. Partitioning used an inverse watershed algorithm to isolate peak domains in directional wave spectra. Wind sea peaks were identified using directional wave age criterion. Wave component clustering was used to form time-evolving systems from the partition results. Resulting wave systems can be traced to a specific generation region on the ocean surface. Wave vector history plots showed that the Trinidad wave field was typically a mixed sea and regional swell field with occasional long-period swell events from distant storms.

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