Algorithm 1 Proposed MSAO Algorithm

Require:  Coordinate of the AUV $p_{a,t}$, coordinates of the current target CH $c_i$, coordinates of the next target CH $c_j$, UAC communication radius $d_{ac}$ and UOC communication radius $d_{op}$.   1:if$d_{se{g}_i}>d_{ac}$ and $m=ac$ then   2:    Calculate the data collection hover position $p_{c_i,ac}$ by (22).   3:    Calculate steering angle ${\mathrm{\Psi }}_{ac,t}$ by (23).   4:else if$d_{se{g}_i}\le d_{ac}$ and $d_{se{g}_i}>d_{op}$ and $m=ac$ then   5:    The data collection hover position is the vertical foot $p_{r_i,ac}$      from $c_i$ to the segment $\overline{p_{a,t}{c}_j}$.   6:    Calculate steering angle ${\mathrm{\Psi }}_{ac,t}$ by (23).   7:else if$d_{se{g}_i}>d_{op}$ and $m=op$ then   8:    Calculate the data collection hover position $p_{r_i,op}$ by (22).   9:    Calculate steering angle ${\mathrm{\Psi }}_{op,t}$ by (23). 10:else if$d_{se{g}_i}\le d_{op}$then 11:    The data collection hover position is the vertical foot $p_{r_i,op}$      from $c_i$ to the segment $\overline{p_{a,t}{c}_j}$. 12:    Calculate steering angle ${\mathrm{\Psi }}_{op,t}$ by (23). 13:end if Ensure:  The steering angle of the AUV: ${\mathrm{\Psi }}_{m,t}$.