Assertion: diver | /r/HasProperty | engaged in marine biology
Facets:
Source sentences:
text: Except on ascent, closed circuit rebreathers produce no bubbles and make no bubble noise and much less gas hissing, unlike open-circuit scuba;  this can conceal military divers and allow divers engaged in marine biology and underwater photography to avoid alarming marine animals and thereby get closer to them.
text: this can conceal military divers and allow divers engaged in marine biology and underwater photography to avoid alarming marine animals and thereby get closer to them.