The court in St. Petersburg on Thursday set bail for Australian Collin Russell at two million rubles (US $61,500).
Russell was the only activist denied bail at the start of the hearings last week.
Two Canadians — Paul Ruzycki of Port Colborne, Ont., and Alexandre Paul of Montreal — were released on bail last week but remain in Russia.
The 30 were detained in mid-September following an attempt by some of the activists to scale an offshore drilling platform owned by state-owned natural gas giant Gazprom.
All but Russell have now been released pending trial. They were initially accused of piracy, but authorities later revised that charge to hooliganism.