Oar Length and Boat Size

Now I realize this is primarily a group to discuss "cruising" and it's
rather difficult to comprehend "cruising" in a boat with oars operated
manually by a wheezing old geezer; however, my sometimes fertile mind
comes up with these scenarios and what better place to find the answer
than in rec.boats.cruising, the hangout of some of the brightest minds
in boatdom.

Prologue accolades aside, here is the problem(?).

1--I've already bought the Suzuki 2.5 hp outboard for our open utility
boat.

2--The boat is 14' 6" long with a 61" beam, 50" bottom width and
approximate 26" side depth.

3--In case the ultra-dependable Suzuki should fail or (gasp) run out
of fuel with no more present in the boat, I would have to row the $#@[EMAIL PROTECTED]
 thing back to shore.

4--The oars I currently possess are 7' in length and they worked fine
for the dinghy we previously owned.

5--My concern now is that they may be too short with the wider beam
and higher side depth for my monkey arms to maintain a grip on them
while they dip sufficently into the drink and propel us forward.

Is there a guide anywhere that would determine proper oar size (i.e.
length) for an open rowboat that would take into account the
measurements of said rowboat?

-Jay
(trying to cover all bases before heading to the open sea...# : ^ )