Repowering a 54' Donzi Sportfish

Looking good, you sized the shaft lengths nicely to maintain the right gap length between the fwd prop hub face and aft strut barrel face.

You've gone through all fo the right stuff here in terms of the scope of your project, but noting, have you dropped your rudders? I wish I had last fall........just sayin....

Also I tried a trick last year, and I used prop speed on the bottom of my trim tabs instead of bottom paint. Thus far working well.

I was actually wondering if those blades are OEM: they look unusually long to me.
But I'm only comparing them against the prop shaft height, not vs. other SFs - let alone the Donzi 54 specifically.
Maybe that's normal in SFs, for granting a better maneuverability at low speed?
Regardless, I can't think of any logical reason for that very low anode position on the blade.
Impressive job overall, anyway!

Your rudders are the same as my originals. Although I replaced them with the newer hatchet design that Roscioli is using now. I'm curious, is a zinc needed on the rudders? I never had a zinc on the rudders or the shafts. I was told that the two large hull zinc plates on the transom where all that was needed, being that everything was bonded to them

If you don't have a bonding wire going to the rudders inside of the boat, then yes, you should have rudder zincs.

I had a similar issue were the starboard trim tab zinc would not last a full year compared to the port side. The bonding wires in the lazarette was in need of replacing. After totally replacing all the bonding wires, ground terminal blocks and replacing the two 50amp galvanic isolators from the lazarette to the engine room. I now only need to replace the to zinc plates and they now even wear less. The bonding wires are often very much over looked and need maintenance.

Well, I was only wondering because most of the rudder anodes I've seen were further up, much closer to the hull.
But to be honest I don't think that can make any meaningful difference, and I surely wouldn't bother drilling another hole and close the existing one.
If it ain't broke, etc.

I wouldn't feel comfortable relying on the transom anodes alone as D54 said, though.
Of course, the "if it ain't broke" principle still stands, but you never know: anodes can be more or less necessary depending also on where the boat is moored at any point in time, not just on the boat itself.
In the example below, everything is bonded to the big round transom anode along the centerline, rudders and shafts included.
But also the specific anodes still wear out a bit. And if nothing else, they are a safety net, so to speak.
I mean, bonding wires connected to moving parts can be not as effective as other bondings, like those to seacocks for instance.
BTW, the pic below shows also anodes on top of the prop nut.
I've often seen them used as an alternative to shaft collar anodes, and I can confirm that they work well.

I'm on the side that over protecting a boat is a mistake if not necessary. A good topic for another thread.

I agree. Spread the protection and protect the protection. It's a solid general rule. Heck, it also helps you understand where to begin to look when a problem appears.

Not disagreeing with the general principle, but for shafts and rudders, I think your boat is actually more an exception than the norm.
Coming to think of it, I can't remember to have seen any boat with neither shafts nor rudders anodes.
In fact, in both cases, dissimilar metals are widely used in these components - like s/steel and bronze, but not only.

Besides, no matter how good the bonding, if nothing else it's a helluva long way to reach your transom anode plates, at least from the props.
In fact, anodes should be not only properly bonded, but also placed within 3 feet or so from whatever component they are meant to protect.
So, you can see why I wouldn't consider shafts and rudder anodes an "over" protection.

Mind, 3 feet is just a rule of thumb, and I'm not suggesting to take it religiously - btw, since I'm used to metric, I normally refer to 1 meter, which is actually a tad more.
But relying only on the transom anodes necessarily implies a MUCH longer distance.

By chance, did you ever measure the resistance between the props and the transom anodes?
If you never did, in your boots I'd take the first opportunity when the boat is on the dry for a very easy check:
Just connect a multimeter to the transom anodes on one end, and to a prop on the other hand.
If you will read more than one ohm, you'd better add some dedicated anodes.
And if you will read less, I'll eat my hat!

No I have not checked the resistance with a ohm meter, don't know if that would be accurate anyway. But I do check the underwater metals with a multimeter and a silver-chloride electrode set to millivolts. Very easy to do while the boat is in the water. If I am not mistaken that is the way it should be done.

Wow. It's not so common to hear of that on a pleasure boat, let alone a plastic one.
Sorry if I was teaching you how to suck eggs.
Out of curiosity, what sort of readings are you getting, and how did you determine your baseline?

Nice to stick to your plan and do it right, probably a trickle down approach from your shipyard business, good on you.

I had a 48 Egg Harbor Flybridge project way back when, similar in that it needed a redo and had a lot of old stuff that was cut in and looked funky. Realized it was easier to build an aluminum console in the shop, lay it out the way I wanted it, had all the right cut-outs and ergonomics, painted it in the shop, then just cut and pasted it in place, everything went together real well and it did not take a lot of downtime.