This paper presents the architecture of Maritaca, a cloud infrastructure for mobile data collection. The system allows the user create mobile Apps for data gathering using simple interfaces, no programming skill is needed. The platform collects conventional data and, in addition, allows to collect multimedia, location information, sketches, barcodes, etc. The collected data can be shared, allowing the formation of small networks for sharing of mobile data. The data is stored in a scalable cloud infrastructure, based on Cassandra and Hadoop products. The system is based on free software and can be accessed in the following address: http://maritaca.unifesp.br. © 2013 IEEE.