Continuous GPS campaigns over the last few decades have brought an unprecedented look into the behaviors and processes that drive subduction zones. A major discovery during this time has been Slow Slip Events, which release tectonic stress over longer periods than earthquakes. Although slow slip occurs in a variety of places along a subduction interface, a particular place of interest are those slow slip patches that occur offshore and near the subduction trench since these may trigger damaging tsunami earthquakes. While onshore GPS have been able to model these offshore events with some resolution, offshore resolution is always limited with onshore geodetic networks. Recent advances in geodesy have placed seafloor geodetic instruments directly above the slipping patches. I evaluate the time-dependent behavior and range of potential seismic moments of slow slip event that took place offshore Gisborne New Zealand in 2014 while incorporating realistic elastic properties and co-inverting onshore and offshore instruments. The results indicate a significant decrease in uncertainty when using the offshore data while the heterogenetic properties result in an increase. While the realistic elastic properties show a decrease in peak during the slow slip event, they create a higher seismic moment. In addition, the addition of offshore data moves the onset of the event several days sooner and significantly increases the most likely seismic moment. The study showcases the use of newly available seafloor geodetic data for resolving offshore deformation.Includes bibliographical reference