In parallel with DONET construction, DONET2 (the second phase of DONET) has started since 2010 to monitor a wider region; the monitoring area expands to the west side of DONET. It will be a larger scale compared to DONET and observatory equipment is scheduled to be installed on 29 stations at offshore Kii peninsula. DONET2 will consist of a 450km length backbone cable system with 2 landing stations, 7 science nodes, and 29 observatories (the landing locations remain to be determined). The subsea construction will start at the beginning of 2013 for starting operation in 2015. Additionally, two more observatories will be added to DONET.