The court in St. Petersburg on Thursday set bail for Australian Collin Russell at 2 million rubles ($61,500). Russell was the only activist denied bail at the start of the hearings last week.
The 30 were detained 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 been released pending trial. They were initially accused of piracy, but authorities later revised that charge to hooliganism.