Here you go, pictures and everything. Bought a pristine 20 year old Daysailor this spring, and couldn't bring myself to drill obvious holes. Finally gave up and drilled two on the face of the upper teak rear compartment slat in order to both back with an aluminum strap the RAM mount for the chartplotter and the teak drink tray. But I needed power for my 55lb 12V Minn Kota and could not fit a 100AH lifePo4 battery under there unless laid on its side where it would get wet, so...the battery goes in the starboard lazarette on its side tucked under the deck, elevated an inch by a PVC trim board to keep it dry.
While I can fit under the deck, a 4" access hatch is pretty convenient to reach in behind and deal with the back of those bulkhead fittings from up top. The only unsealed hole is for the transducer cable.
So the Minn Kota...the boat lives on a relatively mellow lake and the 100AH lithium battery (solar recharged) easily gives me a 10+ mile cruising range at decent speed with no problem. I did fit an ABS foil/fairing to the shaft of the Minn Kota as a round tube is not efficient, but found the prop testing pretty interesting - the maximum amp draws reached revealed that our Suncat hulls are apparently very efficient. These were all MotorGuide propellers - I don't care what a generic Google search says, they will absolutely fit if you use a thick enough washer(s) to get past the threaded prop shaft shoulder to allow the prop nut to tighten. As Minn Kota has a limited selection of mostly large diameter 2 blade props, I was primarily interested in the four blade MotorGuide for it's very small diameter that is less likely to interfere with the rudder and vice versa - I steer from the tiller with a raised/extended rudder to minimize draft while using the motor in a fixed position.
So the props...the four blade MotorGuide Ninja used just over 30 amps at full throttle, pushing the boat to 3.75 mph. The three blade MotorGuide Machete gave the best speed at just under 4 mph, but it's drawing over 36 amps. The fancy MotorGuide Katana two blade performed comparably to the three blade plastic Machete (I did not have the aluminum version). And for those of you wondering about a Kipawa I did try one. Somewhat surprised me but the Kipawa only reached about 3.5 mph while drawing just as many amps as the two higher speed props. I also tested the conventional Motorguide 2 blade which also has a relatively small diameter - very similar to the 3 blade in terms of speed and amp draw, but it also seemed somewhat smoother/less vibration than the others. It may be that I stow a spare trolling motor for the inevitable fail some miles from shore...the 2 blade would lay flatter in the lazarette and the blades probably less likely to be damaged. Just a thought. I should also give honorable mention to the stainless Minn Kota E-Drive I managed to fit. It did over 4 mph but was also drawing more than 36 amps and was going to take drilling the drive shaft to shear pin it correctly and make it look right.
For me, the now discontinued four-blade Ninja (which is pretty much unobtainium other than on eBay at an unfortunate premium) was the best choice given the extremely low amp draw compared to the others, particularly at about 75% throttle when the PWM controller should be pulsing - I was doing 3.5 mph while drawing at most a miserly 25 amps. The relatively minor .25 mph top speed hit against those best performers was not significant to me, and they were drawing 30 or so amps to make the Ninja's same 3.5 mph cruising speed. Minn Kota props were not tested as their diameters are just too large to interest me given the potential for rudder interference.
As for the spare/backup motor wait for the next episode - I have a spare small hub 30lb Minn Kota C2 Endura and lots of props that fit. Be nice if the little MK and the right prop will be enough to drive the SunCat home in an emergency, the thing weighs less than 20lbs.
Conditions were very calm, and no current.