[Rhodes22-list] Electric Trolling Motors

[DCLewis1 at aol.com]

Folks,
 
Another appeal to the list for wisdom and experience.  It’s occurred  to me 
that it might be useful to carry an electric trolling motor onboard in  case 
our OB fails.  My sense is that electric trolling motors are simple,  compact, 
and reliable - I could see storing one under the cockpit seats, or  perhaps the 
laz.  If my perceptions regarding electric trolling motors are  wrong 
(simple, compact, reliable), would someone with experience please correct  me.
 
If anyone has experience with electric trolling motors on their R22, I’ve  
got a few questions:
 
I’ve looked at electric trolling motors, of course they come in different  
sizes and have different max thrusts, but the smallest, lightest, etc I've found 
 are rated at 30 lb thrust.  I have no idea how 30 lb thrust relates to the  
R22, does anyone?  Is it useful at all?  How many kts in flat sea with  no 
wind?
 
I imagine if you had 30 lb thrust, and you were on a river, say the  Potomac, 
you could make 1/2 mi to shore.  I’m not thinking of going  up-river, or 
necessarily back to your slip, I’m thinking in terms of just  getting off the 
river and out of trouble. Any experience that would say that’s  wrong?
 
Has anyone mounted an electric motor on the stern when there is already a  
rudder, swim ladder, and an OB with remote.  What I’m asking is, is there  room 
on the transom or does the electric prop conflict with the rudder?   I’ve 
eyeballed our transom, and I think there is room to fit the motor between  the 
swim ladder and the rudder in an emergency (I could be wrong about  that, I 
haven't actually done it), but I’m worried about chewing up the rudder  and the 
transom.
 
If you had an electric trolling motor, say the type with 30 lb thrust,  about 
how far can you get, on 2 standard auto batts?  I can do the  
Amp-Hr(batts)/Amp(motor) trick, but I don't know how that translates to  distance.
 
Thanks for any info or experience on this topic.
 
Dave