Have you considered and inboard in a small trailer sailer?

[sailingmoonlight]

Sometimes an inboard is a good option.

The prop stays in the water at all times, and you don't have the inconvenience of an outboard hanging off the stern. It can be done. Here are all the details on how I installed an inboard in my small trailer sailer.

[guzzis3]

It depends.

Your boat is open, many on this group aren't. If the inboard is inside you have to deal with heat. Water cooling, through hulls, fadiated heat.

Next there is access for maintenance.

For faster boats there is prop drag and folding/feathering props aren't cheap.

Here in qld we have a 4hp limit for registration. I have been thinking about an electric motor possibly in the bilge and a suitably large generator. There are problems of course, weight, heat, noise, $, but it also has some appealing advantages. Like everything I suppose...

The electric motors offer a lot more thrust than a 4hp outboard which would be appealing for maneuvering, which is all I'd use a motor for.

[sparks_3096]

Some Trailersailers have an Outboard mounted in a well in the Cockpit. Advantages are the motor is easy to start or control, easier to work on and in choppy seas, the prop may stay in the water longer. Disadvantages may include more engine fumes in the Cockpit or deckhouse, limited or no ability to steer the boat from the outboard in the event of rudder damage. Can take up a lot of space in a small Cockpit. Some Skippers have also fallen into the well and injured themselves. Lifting the motor out for service can be more difficult.
I would suggest you talk with your insurance company and get a experienced boat builder to look at your yacht before a major modification.

[svwanabe]

I'd like to see a small diesel with a hydrolic driven leg on the stern that goes up and down like an outboard. The motor could be mounted under the cockpit on a fridge slide thingy like they use on 4x4s so it could slide forward for easy servicing. A bit exy I guess but would be a great set up.

[JimJ]

Did a trip on the Rideau Canal in Ontario in 2019.
The boat was 40ft long.
Had a Kubota diesel motor driving a hydraulic pump. This pump powered the main prop, and the bow thruster and an stern thruster.
It had fwd and reverse for the main prop and boat shaped control (BSC) for the thrusters.
Move the forward part of the BSC port or starboard and the bow moved in the appropriate direction. Similarly with the stern thruster moving the stern part of the BSC caused the stern to move in the appropriate direction.

However if you rotated the BSC, the bow thruster would move the bow with the stern thruster moving in the opposite direction so the boat turned in its own length.

If you move the complete BSC port or starboard, you guessed it, the boat moved in the appropriate direction, port or starboard as selected.

A very nifty system that could be adapted to any boat.
All we need is a small water cooled horizontally opposed diesel engine to power the hydraulic pump.

[zebedee]

I am reminded of electric wheelchair controls!

Generally a joystick is used.
Push forward to go forward, pull back to go back.
Push forward and left to go forward and turn left, etc.

Now here's the interesting bit.
What should happen when you pull the joystick back and left?
Why?

(Clue #1, the obvious answer is not necessarily the best answer, but when I was around lots of electric wheelchairs 30+ years ago, both systems were common)
(Clue #2, think about what happens when you push the joystick left only, with no forward or backward component)

[PaulS]

You turn right as you go backwards?

PS I had a lead acid powered wheelchair go over my foot in the 1970’s and I almost needed one afterwards.....

[zebedee]

You turn right as you go backwards?

PS I had a lead acid powered wheelchair go over my foot in the 1970’s and I almost needed one afterwards.....

Paul wins the prize!

Forward left = right wheel moves forward.
Rearward left = left wheel moves aft.

And the reason this system is better?
Joystick straight to the left = right wheel moves forward AND left wheel moves aft = chair rotates on the spot, a very useful manoeuver in a tight space.