Hauptbootsmann (HptBtsm or in lists HB) designates in the German Navy of the Bundeswehr a military person or member of the armed forces. It belongs to the particular rank group Senior NCOs with port épée.
According to the salary class it is equivalent to the Officer Aspirant (OA – de: Offizieranwärter) rank Oberfähnrich zur See (Marine) and to and Hauptfeldwebel of Heer or Luftwaffe. It is grouped as OR7 in NATO, equivalent to First Sergeant, Master Sergeant, or Senior Chief Petty Officer in the US Armed forces, and to Warrant Officer Class 2 in the British Army and Royal Navy.
In navy context NCOs of this rank were formally addressed as Herr/ Frau Hauptbootsmann also informally / short Hauptbootsmann.
The sequence of ranks (top-down approach) in that particular group is as follows:
Unteroffiziere mit Portepee
The abbreviation "OR" stands for "Other Ranks / fr: sous-officiers et militaires du rang / ru:другие ранги, кроме офицероф"!