Oceans contain 70% of the earth's surface and provide countless benefits to our planet, such as climate regulation, biodiversity, transportation, natural resources, economy, etc. In this talk, I will describe various methods to measure the oceanographic variables that are dynamically significant. The challenges of measuring in a vast and unforgiving environment will be introduced, along with a brief overview of various motions' temporal and spatial scales. Then, pressure, temperature, salinity, density, and velocity measurements will be described using multiple instruments. Next, a brief description of different platforms and measurement techniques (point and Lagrangian) used extensively in observational programs will be covered. I will introduce an extensive International Oceanographic experiment, the Sub-Mesoscale Ocean Dynamics Experiment (S-MODE), sponsored by NASA, and recent frugal measurements in the coastal waters of Bangladesh. I will finish with future sustainable coastal and open ocean observational plans, which will be needed from an Indian perspective.