Answer:
5.5 meters above start position.
Step-by-step explanation:
-Let X be the start position.
#Total distance below the start position is calculated as:
[tex]d_{down}=6+5.5\times 7\\\\=44.5\ m[/tex]
#Total distance above the start position X:
[tex]d_{up}=50\ m[/tex]
#Distance above/below start position is:
[tex]d=X-d_{down}+d_{up}\\\\=X-44.5+50\\\\d=X+5.5\ m[/tex]
Hence, The vessel is 5.5 meters above the start position