traveling underwater / traveling secretly / working secretly, undercover activity

to travel underwater / to travel secretly / to work secretly, to act undercover

matter of taste

seabed

seabed

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

liked, favorite

fondness, favor, favour