Being a man that believes strongly in "The right tool for the job,"
particularly when the quality of the job may mean the difference between damage and no damage, water in the boat vs. a relatively dry bilge, we "splurged" and bought a pair of
ChannelLock 8WCB - 8" Extra Wide Capacity Code Blue® Adjustable Wrenchs. (N.B.: At least I
think those are the ones we have.) Was actually The Admiral that spotted 'em on the wall at the tool store. Our packing nut and the locking nut need 1-5/8" wrenches. But most wrenches that are or go that wide have big, long handles. These were listed as "1-1/2 inch, plus." Well the "plus" was another 1/8" - perfect!

Not only are the handles a lot shorter than those on any other wrench with that kind of jaw size, but the entire wrench is thinner. A pair of those worked perfectly for me.
Jim