I posted some material to indicate why the ocean is important to climate and carbon uptake. The oceans are hard to study and model because they are vast, complex (differing in currents, salinity, chemical and biological content), deep, salty, cold, stormy, and pressure increases as you go down.   Many ocean areas fall out of any national jurisdiction....but many ocean processes cover vast ocean areas (for example the Global conveyor belt) Satellites can only give so much information. Ship research is necessary.

Offshore ship research is costly....upwards of 30 K a day. (and onne day doesen't get you far). There are only so many specialized research ships under a few flags, and very few that can operate and conduct research in while moving, and in extreme weather and ice. Most world nations do not have these ships. Many science ships are getting older, and science budgets are getting smaller (for this type of research) and costs are in creasing. Only a few nations have science budgets to do research beyond their own coastal areas.

There are only a few pieces of specialized equipment that can operate remotely collecting data on the deep ocean. Again, they must be built big to withstand pressures, storms and hazards.. They must be able to be efficient...as they operate on batteries in a cold sourrounding. They are very expensive and to be most useful be able to pass information on to sattelites. (Gliders, moorings, pop up equipment are a few).