4.8m runabout out fishing most of the day with 3 POB. After moving a couple of times the last time appears to have drained the battery while lifting the anchor and they couldn't get the enging started.
We provided a jump pack that they used to start the engine and get themselves home.
Links:
[1] http://www.coastguardmana.org.nz/users/mark-presling
[2] http://www.coastguardmana.org.nz/users/portersnz
[3] http://www.coastguardmana.org.nz/users/katestewart
[4] http://www.coastguardmana.org.nz/users/neil-cornwell