Thank you very much for the trouble you have gone to sending me details of your clever suggestion. I never thought of using an Mist Generator!
Thanks again.

Cheapest way and one ofthe most efficient is to use a 'Mist Generator' rather than smoke. Uses far less energy to power as you are not heating an electric element. I have made one recently for my trawler and it works a treat. The only setback is they need 24 volts , I have used 2 lipos in series. The Mist Generators are very cheap, I bought 4 from Hongkong for about £12 incl.p&p. They need about 12mm of water above them, too much and they will not work, if the water gets too low they have a clever cut off. Use distilled water not tap.
I made mine using a CLEAR plastic container with a full plastic screw lid about 4" diam and 4" deep, make it deeper if you have the space reasons coming up! Use a tube for ducting the mist up the funnel, I used a 22mm piece of overflow plumbing pipe. Make a hole in the lid to accept the pipe, a tightish fit allows for easy adjustment up and down. Also in the lid you need to fit a small fan to encourage the mist up the pipe so keep the hole for the mist pipe to one edge of the lid and the fan hole opposite. I used a fan from a defunct 320 amp speed controller and powered is from 3 x aa batteries. You need to fit a plate just under the hole for the fan to prevent any water spitting up into the fan electronics, obviously the deeper the container the lest chance of this happening. Before going any further you need to calculate the length of 22mm pipe needed so site the unit in position in the hull so pipe lines up under the funnel, now measure distance between the bottom of the container and just short of the top of the funnel. From this dimension deduct the height of the Mist Generator (MG) as this will be mounted on the base of the pipe. Measure the inside height of the container and deduct the height of the MG less about 5mm, mark this distance up the pipe and another about 5mm from the bottom of the pipe where the MG will fit. Between these 2 marks cut 2 slots, top to bottom as wide as possible leaving just 2 small strips of plastic again about 5mm wide each. The 2 slots allow the air flow from the fan to go up the pipe and allow water onto the top of the MG that now needs to be attached to the bottom of the pipe, I used a couple of elastic bands through the slots. A further hole needs to be made in the lid to take a grommet to accept the electric wires from the MG unit. Screw the lid assembly into the container and push the pipe down so the MG is just shy of the container base. Fit the whole unit back into the hull, use a funnel to pour some water into the unit covering the MG by about 12mm, connect the power, switch on the fan and away you go.
Hope this helps.