The SIMRAD TP 22 is declared to be suitable for boats up to 5000kg. Can be interfaced with a chart plotter. It came with the boat I just bought and given I have the TP 32 from my previous boat, that is what I will keep. The unit has been tested under sail and engine and it did steer the course as it is meant to do. Retail price is $1300 so I guess it is a bargain. It comes with the connection and water tight plug but not with the attachment which can be bough separately.