Summer Scenes in New York Harbor

Crew racing in busy New York Harbor in the late 19th. century, except these are 6 oared sweep shells without cox (at least, I can't see any), boats not used in today's crew scene. Having seen how important the cox is in 8 oared sweep shells, I can't imagine a 6 oared sweep shell without a cox.  Is there a history expert in the field of racing shells who can enlighten me on this?  The one thing I do know is that Currier & Ives published pictures which were historically accurate.  Maker is R.H. Barbour, 1970's, plywood, non-interlocking. Artist: Currier & Ives.