Toy Boat
My first thought was that there should be a commercially available 'toy' which I could readily convert as virtually no cost to use as a rudimentry bait boat. After a good deal of time looking at ebay (my favourite place for baitboat bits) I thought I'd come up with a solution! For around £30 you can buy a small amphibious tank toy (see below). Conversion is a simple case of cutting the wheels of with a hacksaw and attaching some containers to hold rigs and bait.
Hopefully you'll get the idea here. None of these images are mine. My boat is now in pieces somewhere in my shed! Plenty of others have had the same idea and there are You Tube videos of these...
Although this actually did work, I had many issues....
Bouyancy was an issue. It sat very low in the water.
The boat also leaked badly despite my attempts at sealing it.
Battery life was dreadful...I made 7 return trips on a full charge of about 30 yards.
Despite the problems I was overall quite pleased with the result! I originally thought that all I would need to do was get a bigger battery and sort out the leakage and all would be well. Sadly the bigger battery was too heavy for the boat and the overall design meant that the motors were submerged in water the whole time. I had at least proved that for a small outlay I could get my bait where I wanted it. I wanted to do better though and decided to build my own boat from scratch.