The "standard" Sea Nymph 14' aluminum boat has a lower HP and capacity rating. The "Big Water" model will accept a larger outboard and has a bigger beam and depth. Some years they referred to the "R" as "rugged duty".
It's not the nicest boat I ever owned, nor the most expensive, nor the fastest, but its the boat my family had more fun in and its the only one that will never get sold.
My 2 boys were raised in that boat. It held 2 adults and 2 teenagers and still comfortably plied the waters of the Great Niagara and Saint Lawrence Rivers.
Its noted for rib breakage, but sistering them with 1/4" aluminum easily fixes the problem. Don't go over 18HP, though. A 25 is too much for that hull.
Ours is 55 years old this year and we've owned her now for 33 years.