ABSTRACTThis study aims to observe tidal sea behavior in Bay of Sabang by using a two-dimensional hydrodynamic model. The research domain was obtained from SRTM15, which had been interpolated so that it has a spatial resolution ?x = ?y = 0.1 minutes (185 meters). As a generator force, the open boundaries model is given five main tidal components (M2, S2, K1, N2, O1) obtained from TPXO 7.2 data. The model is simulated for 31 days with time step based on CFL condition criteria. The verification point on TMD is placed at Lon coordinates = 95.2733, Lat = 5.8767 (X = 33, Y = 26) when Neap tide is on Ebb Current condition. This model verification is quite good when compared with TMD prediction data (r = 0.9996). It shows that our model can be used for tidal hydrodynamics studies in Bay of Sabang. The results show that tides in Bay of Sabang are predominantly mixed prevailing semi-diurnal (F = 0.857). The speed of tidal currents in Bay of Sabang is quite small both for spring and neap tides. The difference in velocity between spring and neap tides reaches 0.6 cm/s, where the highest current speed at spring tide is 0.8 cm / s and 0.2 cm / s at neap tide.Key Word : Tides, Refined Spring, Hydrodynamics, Spring Tide, Neap Tide, Sabang BayABSTRAKPenelitian ini bertujuan untuk mengamati gerak serta karakter pasang surut laut di Teluk Sabang dengan menggunakan model hydrodinamika dua dimensi. Domain penelitian diperoleh dari SRTM 15 yang telah diinterpolasi sehingga memiliki resolusi spasial ?x = ?y = 0.1 menit (185 meter). Sebagai gaya pembangkit, pada open boundaries model diberikan lima komponen utama pasang surut laut (M2, S2, K1, N2, O1) yang diperoleh dari TPXO 7.2 data. Model disimulasikan selama 31 hari dengan time step berdasarkan kriteria CFL condition.Titik verifikasi pada TMD diletakkan pada koordinat Lon = 95.2733, Lat = 5.8767 (X = 33, Y= 26) di saat Neap tide pada kondidi Ebb Curent. Verifikasi model ini cukup bagus jika dibandingkan dengan data prediksi TMD (r=0.9996). Ini menunjukkan bahwa model kami dapat ...