More than 60 bags each filled with 25 kg of cocaine were found, the ministry of defence said in a statement on Wednesday. All ten crew were arrested, Radio Television Guineenne added.
Drug smugglers often use West African countries as a transit point to ship cocaine from South America to Europe.
Cocaine purveyors chose this route after shipments directly from South America to Europe gained too much scrutiny, hoping that cargo from Africa would be seen as less "suspect."
About three tons of cocaine were seized in August last year from a ship anchored in Guinean waters.