  The Prototyping phase of the BAIKAL-GVD project has been started in April
2011 with the deployment of a three string engineering array which comprises
all basic elements and systems of the Gigaton Volume Detector (GVD) in Lake
Baikal. In April 2012 the version of engineering array which comprises the
first full-scale string of the GVD demonstration cluster has been deployed and
operated during 2012. The first stage of the GVD demonstration cluster which
consists of three strings is deployed in April 2013. We review the Prototyping
phase of the BAIKAL-GVD project and describe the configuration and design of
the 2013 engineering array.
