As far as I can see, those super core
generators produce DC??? It indicates that the rectifiers are inside the units.
That SC24 looks okay. You're gonna need an indication of how fast your shaft is turning so you can select pulleys. You're gonna need a minimum os 1400 rpm on the alternator for charging
a 24V system. The question is how many hp you generate. Every hp equals 745W. So, if you make 1400 rpm on the SC24, it will supply 50A at say 28V which equals 1400W so it'll need 2 hp power from the prop+shaft. If your prop+shaft can't supply 2 hp, the SC24 will spin slower or not at all.
Now let's say you go faster (or use different pulleys) and you spin the sc24 at 3000 rpm. Now you get 112A at 28V = 3136W equals 4.2 hp.
Don't forget you need a fan to cool the SC24. The rpm's you make have a linear relationship with how many cubic feet per minute the fan displaces. If the SC24 runs too hot, you are going to need more rpm's or a different design fan-blade.
All in all a nice experiment
if you have your prop spinning when under sail. I would get a whole bunch of pulleys and a couple of fan blades and experiment
to find the best system. I think the SCS18 at 2500 RPM is a better option or two SC48's at 1500 RPM... many possibilities.
You need someone who can calculate how many HP you can generate with your prop + shaft. Remember that you will have losses in bearings and the gearbox!