have to agree with Dave here [yet again!] . an 800 [or 700BB turbo] is a reasonable size motor, but running a 75mm prop is going to pull the rev's down and drain the batteries quite quickly. id either run smaller props, say 50mm max or if determined to run the 75mm's then use a 3:1 gear ratio to reduce the revs but increase the torque to drive it.

cheers for the advise dave, I will take that onboard,pardon me no pun intended 😁

HI 0116tbone
I suspect you will need something like an 800 motor for this size boat.
It is very similar to the RNAS Exploit fast patrol boat and that runs well on two 850's with 12v SLA's. Weight will not be a problem as you will need plenty of ballast. 😀
Toylander
I think a 600 will be overloaded with a 75mm prop unless you plan to fit a reduction unit. 😓 An 800 motor would suit your model but may also need a reduction unit if you plan to keep the 75mm prop. A friend is restoring a Sea Queen and he is using a large brushless motor.
HI Gregg good to hear you are keeping busy, and paying taxes to fund my OAP 😊

Well, Im a Safety, eligibility & Environmental Scrutineer, so not only do I get close up to some of the nicest racing and rally cars, I get paid for being there too!
Can't be all bad, can it [ha ha].

now motorsport thats my first pasion 👍

No worries tony, "some" of do still have a "working career", unlike those fortunate ones that have retired and have all the time in the world! [betta run fast now I've said that] 🔨
I work in the critical care unit of a Hospital and work weekends for Uk motorsport, act as secretary for a boat club and.......... you get the picture [ha ha].
its no wonder Ive hardly got anything in stock in the fridge !

HI Greg, I work as a store detective which means six days aweek solid,not the best job to have a hobby hey. 😁

HI Tony.any news on the overall weight yet?

HI there, I'm studying the plans for a sea queen build, it's a 46 inch long cabin cruiser and uses a 75mm/3" prop. The original used a 3.5cc diesel engine so can't really comment on electric motor choice, but I will probably start with a speed 600.

no prop fitted yet, I will get back to you with the weight asap.
Thanks Tony

Whats the actual weight of the boat? I did ask in my reply. its something that needs to be taken in to consideration. Also what size is the rudder thats fitted. Haave you, or is there a prop shaft installed, if yes, what size is the prop thread and how far is the prop end spaced from the hull?

This then allows the prop size to be calculated. if no prop fitted, then alls the better. I can work something out for you, no problem.

cheers greg, I think I'll go for the cruise and a bit of an umph even with the radio gear in she still is quite light for her size.
Many Thanks
Tony

The size/capacity of the motor depends on what you would like the boat to do, "performance wise". I could suggest a motor/battery size that will let it "tootle along" all day, or suggest a motor with a bit of performance, so it give you cruise and a bit of "go" too.
What is the all up weight of the boat? length is one thine, actual weight is another factor.