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I am considering ordering the Billing Boats White Star kit. This will be built strictly to the instructions except for custom paint on the hull exterior. There will be no deviation or modification for the deck, cabin, bridge and deck hardware layout. I have not decided yet whether I want working navigation lights.

What I am concerned about is the fitting of the battery, RC gear and motor. I think the lightest most compact RC components will be ideal. I don't need a lot of speed and power. I want my boat to cruise at a leisurely 25 scale knots or 2 actual mph on a relatively smooth pond.

I understand that RC battery packs can be rather light and compact these days. Do they use modern lithium rechargeable technology? The battery pack has to be positioned in the hull for good balance so the attitude or pitch of the bow is correct and the boat does not heel over.

The motor should be as small and as energy-efficient as possible at a modest 2 actual miles per hour. I hope to get away with a single motor and a single-screw drive system. A model fishing boat is not a race boat and should behave in scale accordingly. Keeping the RC components modest but reliable in performance should also help keep the cost down.

I have Futaba in mind for a two-channel radio and rudder servo.

What battery pack, charger, motor and controller do you recommend for this model?
I have not yet bought the kit nor have seen the plans.

Ideally, I would like the battery pack installed for quick easy
replacement with a freshly-charged pack at the pond. The deck top
cover will be designed for removal to access the RC works in the hold.

https://www.woodenmodelshipkit.com/p...ts-white-star/

Here is my custom paint concept for this scale lady of the pond:

mfr02

I suggest a bit of on line research. This is a 21 inch long launch, any number of them feature on model boat threads. I picked up a lot of useful information reading such threads.
At 1:15, 25kt full size gives nearer 7.5 mph scale. Divide the speed by the square root of the scale, not the scale.
I've had a Graupner Lotse (similar size & performance) doing long, fast runs using a 7 cell NiMH pack driving a Speed 400 motor for that voltage. I can cruise it round my lake, a 1 mile walk, without any problems. In practical terms, when the battery gets low, it's time to go home anyway. Using modern technology might improve it, but I can't be bothered.
Try not to over-think problems. Usually, they just get bigger, don't get solved and the thinking becomes a displacement activity that puts off the build.
Have a look here http://eezebilt.tk/index.html for a simple low cost learning experience that will answer many of your questions regarding the general principles of model boat making.

[email protected]

It only seems logical to divide the full-size speed by the scale. Think of this: at 25 knots, the full-size boat will travel her own length, 26.25 feet, in 0.622 seconds. Ideally, the 1/15 boat should travel her own length, 21", in the same amount of time to be at the scale speed of the 25 knot full-size boat. This comes out to 1.92 actual statute miles per hour for the 1/15 boat. Roughly, 2 mph.

Using this scale speed calculator jibes with my reasoning:
http://www.mcr5.org/articals/speed.php

mfr02

Shakes head sadly, departs.

Dodgy Geezer

Alas - model boats are not logical! Or rather, they are, but you are going about things the wrong way. Scale effects are very important as we move into model sizes, and they completely negate the simplistic example you have provided. Perhaps I can quote a similar example by the famous boat modeller Harvey Adam, from 1951. I précis a bit:

"...If a full-scale ship of 300ft travelling at 20mph is modelled at 1/100th, making it 36", it should travel at 1/5th mph - which is inadequate to make headway. It will work better at 3-4mph, but it will look ridiculous if it goes any faster. If a 36ft speedboat travelling at 40mph is modeled at 1/12th, similarly making it 36", it will be able to make headway at the scale speed of 3.3mph, but will not sit on the plane like the prototype. To do this the model needs to travel at about 10mph...."

This is a well-recognised issue whenever we consider relative sizes - read J S B Haldane on the subject: http://www.phys.ufl.edu/courses/phy3...eRightSize.pdf

Many modellers use brushless motors at the moment - these provide high performance. The EeZeBilt series of boats mentioned above - roughly similar to yours, have the fast boats designed around an EMax 2822 KV1200 brushless motor with a 35mm prop. This gives a reasonable fast plane.

The problem with brushless motors, particularly small cheap ones, is that they do not have flexible low speeds - they are a bit like an I/C engine in this regard. If you want flexible low speeds, a brushed 380 - 400, as recommended above, will suit.

[email protected]

Ok, I see now. It more about trying to scale the laws of physics FOR WATER-BORNE VESSELS. Headway, plane and such. Train modelers use the simple scale speed approach, but they are on dry land, train tracks. They don't have to deal with the complex dynamics of wind and water currents. A scale deep-vee fishing boat at 1/15 scale will probably not be on plane when traveling at an aesthetically-pleasing speed for the persona (character) of this model.

canabus

A 28mm single brushless motor(1000to 1500kv) with a 30-32 mm 2 blade prop and Lipo battery about 2650mah.
Hobbyking gear is reliable and not pricey.
The Lipo batteries are about the same size as the NiCad packs but have far more power and far longer run time.