at the menezes bus terminal, the bus 'castelo x itaipú' nicknamed frescão, and operated by auto viação1001 gets to praia de itaipú in about 90 to 100 minutes. 

typically the buses on this line have comfortable chairs normal on inter-regional buses.  

this link shows praia de itaipú on a wikimapia  - the satellite view as we present it is best seen using google chrome, as zoom settings might not open correctly with other browsers.