Data Set S1. 
This is the data file for seafloor benchmark positioning.
Eleven element data is contained in this file; 
[1]Time, [2]unit number, [3] travel time, [4]X, [5]Y, [6]Z, [7]Heading1, [8]Rolling1, [9]Pitching1, [10]Heading2, [11]Rolling2, [12]Pitching2.

Explanations for each elements are 
[1] Time of ping (emitting the acoustic signal), [2] # of the pinged seafloor transponder, [3] One-way traveltime of the acoustic signal, [4]-[6] Tentative position of the onboard transducer in ECEF coordinate at the mid-time of the emitting and receiving the signal (This position will be modified by solving the relative position of the transducer to the main GNSS antenna), [7]-[9] Heading/Rolling/Pitching at the time of signal emission. Definition of Heading, Rolling, and Pitching is CW from North, right side down, and nose up, respectively. [10]-[12] Heading/Rolling/Pitching at the time of signal receipt. 

※ECEF coordinate is based on ITRF2005.