Most of the big cities in West Africa are located along the coast. These cities are vulnerable due to the climate change. The coastal issues are not understood because few studies have been undertaken due to the lack of limited dataset. During these last ten years, many regional programs (ODINAFRICA, PROPAO) have been implemented to collect in situ data. This study combines the previous data and those acquired by the new equipment to investigate the Gulf of Guinea coastal issues. Harmonic analyses based on three software were performed to determine the harmonic constituents in the aim for tidal prediction. Gaussian filters were applied to altimetry data and tide gauges records for sea level anomalies time series analysis. The tides are well described by the three software. All these packages give globally very similar results of the harmonic constituents. The tide gauges records are well compared to altimetry satellite data along the West African coasts. The rate of sea level increasing is comparable with that observed at global scale. However, the African coasts remain vulnerable due to the lack of adequate prevention systems in the case of extreme marine events.