Give you a few observations not mentioned. You want Binoculars to suit the job . Standard marine glass has always been a 7x50. Lower power less shake from engine vibrations good low light ability size and weight not important, they usually ride in a fitted box on the bridge, Lower power easier on,your eyes scanning. Hunting most game same thing applies except you want a smaller glass with less bulk and weight 7x30 is a good choice. Its no accident WW II the Navy used a 7x50 while the Army carried a 6x30 in the field .
Bird watchers use much higher power the target is small & most take a quick look to identify a bird add it to their list then move on. 10 power bird watchers binocular will tire your eyes scanning. There could be good use for a high power glass varmit hunting but spotting scopes much better for small animals. Deer size game you dont need high magnification
I use 4 glasses Swarovski 7x30 general use & a very small pair of Swarovski 8x25 for very light weight use. Either one a top glass probably no better than other top brands. Other two are Vintage B&L , 7x50 Bureau of ships and a Army issue 6x30 both restored.The old glasses are nearly as good visually as the Swarovskis not water resistant or fog proof like a new glass. Lens not coated,they will flare in adverse light .
Biggest mistake in a binocular is too much power. Thing that affects what you see the most is objective lens size. Bigger the better until its too big to carry.
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