Why naval commissions were not purchased

Were the many Franco-Spanish officer commissions purchased?

No. Naval commissions were not purchased in these fleets, because competence at sea imposed professional demands that wealth alone could not satisfy.

Naval commissions were not purchased in the British, French, or Spanish services under discussion. Sea service imposed practical tests that money and social standing could not reliably overcome. An officer still needed professional knowledge and the ability to function aboard ship. The contrast helps explain why purchased commissions survived longer in armies than in navies.