Today was the first time I had my new boat on the water. Inside one of its hulls was a GPS device and a Linux based computer recording its position. Also running was the sensor board which enables monitoring of current coming from the solar cells and current consumed by the boat. It didn't exactly do very much however.

Both hulls are now complete, and the solar panels attached. The purpose of its test today was to investigate some of the features of the hull design. First of all it floats. Solar panels and heavy lead acid batteries were not too heavy. The waterline is about half way down the hull. This was no great surprise as I had tested this for each hull in the test tank, otherwise known as the bathtub.

I wanted to know how much energy it required to propel it. A small push from the rear and it would glide effortlessly forward. So much so I had to chase it. Pushing sideways was a totally different story, resisting any effort to be moved sideways. Turning involved more energy that moving straight ahead, but not nearly as much as pushing sideways.

I conclude that the decision to design this prototype as a catamaran achieves the design objective of providing a more directionally stable boat. This will aid in maintaining a heading. The unsurprising lack of leaks in the boat was due to using materials that were far stronger, but nearly as light.

I have also wired up both solar panels to both batteries, and have have both phidget devices working, plus the GPS. I set up the computer to log the position of the boat every second, and it reliably did so for the entire trip.

Another positive discovery was the fact that my boat would fit in the back of my wife's car without disassembly. Just. Generally this means I will boot the boats computer up at home and check all it's systems before taking it to the beach.

Okay, so what is left to do? The most critical aspect to getting things working is a propulsion and rudder system, as it won't be going anywhere without them. Potentially I could use a remote control to test operation without computer control, but with the existing power system.

I also need to solve the power problem. Currently there is a solid state relay which turns the power to USB off and on. However, the onboard power supply can only supply up to 500ma. Beyond that and the power supply will brown out the computer resulting in reboot.

One solution to this is a powered USB Hub. This way the USB devices won't be taking power from the computer itself. This may also mean I don't need to turn USB power on in software. The downside is that I will have no software control over power. That isn't actually a huge problem for now, as fully charged I have 15 Ah of power, and with a power draw of about 250ma as currently measured I could operate for 60 hours without any power input from the solar panels.

However, without the ability to substantially reduce power consumption I certainly won't have a self sustaining boat; that is capable of storing enough power to operate over night or through overcast days. Ideally I would be able to bring up selected USB devices, pick and choose which ones I needed. But for now a continuous operation will make do.

Finally I need to solve two software issues, one with getting a serial driver working for the USB compass, the other compiling and installing the drivers for the USB 3G Vodafone Mobile device I purchased some time ago. Currently I have no communications, not even wireless.

I don't expect to solve all these problems before I begin work once more, but hopefully I will have completed the propulsion and rudder systems.