I wish you hadn’t disclosed that location Starscream. I have been eyeing it for almost 4 years now. It might already be claimed for off-shore diamond mining, since DuhBeers is operating out of Namibia and was claimed to be working on attempts at offshore mining.
The issues as it stands from my research:
UNICLOS won’t allow it to be claimed as sovereign territory. You can work around this if nations are willing to recognize you as a sovereign entity. However if you are American or a number of other nationalities, they will claim sovereignty over any territory you claim to control. This means any Americans, certain Europeans, etc wishing to found a nation and claim territory will need to be legally stateless, utilizing formal renunciation procedures of their nation where applicable. This won’t save you or your vessels from harassment at sea, but will set up the legal foundations towards both self-sovereignty and international recognition.
Minimum personnel and supplies: About 100 people. The smallest island nation I could find was Pitcairn with 50 people residing on it and ~300 expats. Supplies necessary to roll out a basic seamount colony, modeled loosely off Sealand, would be a few dozen shipping containers, sufficient to be welded end on end as the external mold of legs for a platform. concrete or geopolymer precursors sufficient to fill said legs, pipes or i beams in sufficient quantity to weld together platform superstructure, solar/wind arrays (plus batteries) capable of providing 1kW of continuous (24hr) power per person, water purification and septic storage, plus fencing material and aggregates to begin filling in an area under/near the platform to provide a basis for further work. The biggest point of the platform would be withstanding tropical storms (which that reason doesn’t appear to have many of), mark claim to the territory, and provide docking access for further expansion. Once sufficient aggregate is build up, it can be held in place by regular cheap spools of fencing material, hooked or welded together to provide electrical continuity, then be used as a cathode for biorock production, providing the seed structure for a new reef, which given sufficient financial resources and motivation will provide the foundation for expansion over the whole mount, while also helping to enhance the ecology for the existing sealife, or if it turns out sufficiently barren, imported sealife to complement the coral breeds used as starter.
The reason I had not published these plans more widely is because of the risk of the legal landscape being changed to nip these possibilities in the bud before we could enact a colony. Given that Argentina has already gotten its EEZ expanded up to 350nmi, and Argentina has been the test case for the last two expansions of EEZs, we are in a race against time if we wish to found a seastead, nevermind a sovereign seastead, without bloodshed in ‘high sea’ waters. Besides the location mentioned there are only about 3-4 others that are outside of EEZs and in uncontested waters (I would NOT recommend trying to set up anything in the pacific east of Guam/Hawaii/Other western US territories), as they already have plenty of laws on the books they will use for harassment of anyone in their defacto jurisdiction there, especially anyone flying an unrecognized national flag.
If you have any more questions, feel free to ask, and kudos to you Starscream for noticing what a brilliant location that is.