The need to better predict the impact of potential oil spills from deep water wells in the Gulf of Mexico has given rise to various drifter and subsurface float programs over the last decade. In the western Gulf of Mexico, a subsurface float program took place to study the circulation and dispersion at 1500m depth funded by the US federal agency BOEM (2011-2015), and more recently two drifter experiments designed to study dispersion over the inner shelf (ISDEX) and the continental slope (DWDE) were performed as part of the Gulf of Mexico Research Consortium (CIGoM), funded by the Mexican federal agencies SENER-CONACYT (2016-2018). These databases are used to compare and discuss relative dispersion metrics at various time and length scales between regions with very different dynamics: the inner shelf versus the continental slope, as well as the surface versus the bottom layer of the deep western Gulf of Mexico. In addition, the metrics from the observations are compared to those derived from the CIGoM numerical models used to produce oil spill scenarios, in order to evaluate their performance in reproducing the observed dispersion.