Greetings. My 3rd SeaRay is a 1997...

[JoyRide20]

Greetings. My 3rd SeaRay is a 1997 Dancer 330 V-drive. Her two 7.4's are drunk on sea water. In my research, I learned that she has been repowered at least three times. And that scenario is not uncommon with this design/year/model/configuration. So instead of financing a fourth failure, I've researched kicking the gas habit and moving into the 22nd Century with electric motors. I understand about the power and range limitations. Being old, my Need for Speed has greatly diminished. The speed limit in my bay is mostly 5mph. Pounding her out in the deep blue wreaked havoc on my bar and wine collection. All of the required gasser maintenance projects cut too deep into my cocktail hours. I prefer to fish the local restaurants and markets these days. I've already caught my limit of "You're Crazy" judgements. Comments from an experience with a similar conversion would be greatly appreciated. Grassy asss. 

[Sanibel_Life]

I searched all over when repower came knocking. I coukd not find 1 commercially available conversion. Just a bunch of DIYs with small.electric motors. Look forward to hearing yoir progress.

[wingless]

Welcome to the forum.

Too bad about the engine problems.

My understanding is that there was a short run w/ log exhausts instead of the lift exhausts. Those log exhausts were susceptible to engine hydrolocking when getting whacked in the stern by the trailing wake, when coming off the throttle.

If required / applicable, a boat built w/ log exhaust can be reworked to lift exhaust.

The other / more common issue is neglected manifolds / risers / elbows that suffer from internal corrosion when operated in salt water.

A salt water boat must include an annual exhaust disassembly for visual inspection for both internal corrosion and for SOLID wall thickness between raw water and exhaust gas passages.

Zero idea on conversion to electric, but that doesn't seem feasible.

[KC_boater]

You will not find a direct replacement yet.. There is however a company called Ocean Volt that makes DC Drives that are typically used on sailboats. You will need a pretty substantial bank of lithium Ion battery's, . it certainly can be done but I bet it will not be cheaper that replacing with two new gassers. I am trying to design an electric runabout using tesla car battery's.
probably going to be hard to get that one insured! HAHA

[JoyRide20]

Sanibel Life - you are correct. I'm going with two 48v 10Kw motor systems from Electric Yacht Company in MN and16 golf cart 6v flooded batteries. Less than half the cost of two rebuilt gassers. Way less than half the speed, but zero maintenance. Picture a big, heavy, quiet Duffy... but with my 7Kw genset I should have good range.

[wingless]

There would be a very significant cost savings if instead of installing two of these electric motors and batteries, the boat was reworked to add a forward and aft set of oarlocks and several nice sets of oars.

There could even be room for a perch for a person holding a whip at the transom.

The manufacturer does not list anything close to this application for those motors. Each provides short bursts up to 25hp, versus the ~350hp continuously available from the gas engines.

It is very likely that the wind and current will greatly exceed the available thrust, making the anchor critically important.

Please ensure sufficient video coverage, from multiple angles, is available to document the results.

https://electricyacht.com/wp-content/uploads/2019/04/QuietTorque-10-Sport-Product-Data-Sheet-Apr2021.pdf

[wingless]

Four (or more) of these 12V 100A output battery chargers could be added to eek much of the available 7kW generator output back into the rapidly draining batteries. Each permits 100% of the output into a single bank. Probably using two per bank is the best option.

https://www.victronenergy.com/upload/documents/Datasheet-Centaur-Charger-EN.pdf

Does ~$4K of battery chargers change the gas engine versus electric motor decision?

[wingless]

If remaining / returning to gasoline engines, then there is something seriously wrong that must be determined and fixed.

One is the previously mentioned log exhausts.

Another is also previously mentioned deteriorated cast iron exhaust parts.

The exhaust geometry must also be correct, w/ proper slopes and other important dimensions and angles/

Good luck.