I did not find any seamounts as close as 100 m to the water surface (100m from the mean surface level at the location of the mountain) that are not part of any Exclusive Economic Zone (EEZ.)
Do any such seamounts exist?
I did not find any seamounts as close as 100 m to the water surface (100m from the mean surface level at the location of the mountain) that are not part of any Exclusive Economic Zone (EEZ.)
Do any such seamounts exist?
Yes, there are many. According to the seafloor topographic data of ETOPO (1 arc second resolution), and the Exclusive Economic Zones (EEZ) database of marineregions.org. There are at least 157 seafloor features higher than -100 m (closer than 100 m to the sea surface). With that data, I made the following figure that shows:
Some of them are just a few meters below sea level according to ETOPO.
But note that with this data we can only see large features. ETOPO resolution is about 2 km. Therefore, a seamount with a sharp summit just above -100 m would probably not show up on ETOPO data.
For more information about individual seamounts you can query the Seamount Catalog of EarthRef.org. There you can find high resolution multibeam seafloor topographic data for many seamounts, there are more than 1,800 seamounts in the catalog so far.
For example, for Vema seamount that was mention by @arkaia and that corresponds to the point just West of South Africa in my figure, you can find data like this:
Checking the Wikipedia page on underwater volcanoes and listing them by height, I think the best candidate is Vema Seamount. Vema Seamount is in international waters and its shallowest point is at 11 meters from the surface. It is so shallow that it represents a navigation hazard.