Marine heatwaves (MHWs) are extended periods of unusually warm ocean temperatures that significantly impact marine ecosystems. While most studies concentrate on temporal changes at a single point or spatial changes over a fixed duration, the combined daily progression of these changes in both space and time is still largely unexplored. Here, we employ observational data from a three-dimensional perspective (latitude × longitude × time) to examine multidimensional characteristics of Spatiotemporally Continuous Marine Heatwaves (SCMHWs) worldwide from 1982 to 2022. We categorise them into eight types based on duration, area, and mean-intensity. Results of the three-dimensional identification show that there are 6,605 different SCMHWs, of which the most prevalent types are Duration^NormalArea^NormalMean-intensity^Normal, Duration^NormalArea^NormalMean-intensity^Extreme, and Duration^ExtremeArea^ExtremeMean-intensity^Normal. Additionally, SCMHWs mainly spread east-west and move faster than they do north-south. Over the long term, these events have become more frequent, longer in duration, broader in coverage, slower in movement, and have migrated greater distances.