Solar challenge

World’s first solar powered houseboat sets a world record

The Mothership has just become the first boat to travel the entire 150km down the Hawkesbury River using only solar power. The Hawkesbury river is long and tidal. Tides can run at over 4 knots in some places. A trip of this nature needed to be planned to make best use of the tidal flow. The upper reaches are gentile. After Wisemans Ferry the river becomes more of a wilderness and it is rare to see another person. After Brooklyn it gets busy again. Christmas Day was spent in safety and comfort in Americas Bay. We finished on Boxing Day by travelling to Pittwater via the notorious West Head. All of this in our electric boat.

Captains Log

There were 7 of us onboard the electric boat, myself Tim Knox, my wife Sue, our children Sam, Leo and Poppy. We were also joined by Sam’s girlfriend India and Poppy’s friend Jamie.

Windsor 20/12/14 Day 1 – setting off

Midday we set off. No brass band this time. On board we have myself, Sue, Leo, Poppy and her friend Jamie. Sam and his girlfriend India will join us in Wiseman’s Ferry.

The birds tweeted, the sun shone, the Mothership gracefully slid through the water. Then a few cracks started to appear in the family adventure bliss. Leo has had enough and wants to go home, Poppy is restless, Sue keeps asking me to stop so the kids can have a swim.

It always takes a few days to get into the groove of one of these adventures and the first day is always the hardest. 10 miles down stream we decided to call it a day. We got the Lillypad out (thanks All Points Boating). Everyone let off some steam and we settled in for the evening.

I slept on the top deck under a mosquito net. Around 3am I got up to have a look around. I saw a clear sky full of stars but the beautiful thing was, and I’ve never seen this before, the water was so still it was reflecting the stars. Gorgeous.

Technical Stuff

We motored with a SOG (speed over ground) of 4.4 knots drawing 15 amps on each motor. There was on average a 1 knot tide that helped. We achieved this speed with what we made from the solar panels. The SOC (state of charge) of the batteries remained at 100%.

Upper Crescent Reach 21/12/14 – Day 2

Started the day slowly with bacon and eggs and a slow motor against the tide. The aim was to get to Wiseman’s Ferry for the night but because we had stopped early the day before it was a bit hit and miss whether we would make it or not. The good news was that there was lots of sun.

The whole point of this trip was to prove that it was possible to make a solar powered trip down the whole length of the Hawkesbury River and into Pittwater. I was particularly conscious of using the sun’s rays to best effect and not dip into the battery bank just yet.

As a young lad I was in the merchant navy. On several occasions I found myself several hundreds of miles up the Mississippi loading grain. The Mississippi is a powerful river and I used to marvel at the Pushers (tugs that push) force 40 or more barges up the river against the current. That memory was revisited as we in the Mothership pushed against the Hawkesbury’s incoming tide. But with our high torque electric motors and ultra efficient hulls we made light work of the task.

At midday we passed Sackville and got a friendly wave through from the ferry driver. As the tide changed so did our speed over the ground, Wiseman’s we’re on our way.

Still our battery SOC (state of charge) was showing 100% meaning all the miles covers so far today were solar miles.

At 3.31pm we passed mark 902 which meant we were only a few miles from Wiseman’s. The sweet spot for the motor in terms of efficiency is at 550 rpm which gives us good speed and only uses 15 amps per motor. At 4.15am we reach the public mooring at Wiseman’s Ferry and head up to the Inn for a beer or 2.

It’s been a good day – all that way on only solar power. No carbon was put into the atmosphere, no noise either, we just quietly got on with the task of sailing down the river.

3 beers actually.

Later in the evening we welcome Sam and his girlfriend India on board. The Mobile reception is not great here and it takes us a while for us to see flashing headlights from the shore. Oops.

Wiseman’s Ferry 22/12/14 – Day 3

Bacon and eggs again – I’ll do some sit-ups later. We slipped our mooring at 10am and headed into a strong tide. At this point the river turns from fresh to salt water, gets much wider and wilder. It’s my favourite part of the river. The weather is good but the forecast not. We’d been lucky so far but it looks like all that is going to change. It is important that we travel as far as we can today to make best use of the sun. Staying to 550 rpm we push on.

With a river as long as the Hawkesbury the tide peaks at different times. Each cycle lasts just over 6 hours but if you time it right you can stay in the flow for much longer. I was keen to do this but with youngsters onboard there’s a need to have fun. So pleased we have the rubber duck. In this way the Mothership becomes at true mothership as the young go off and discover crabs on the mud or in this case a ‘bunch’ of jelly fish. I don’t know what the collective noun for jellyfish is.

A little wiser they return looking for vinegar to soothe their wounds.

The weather is looking a little ominous and the forecast confirms that we are in for a rough night. We pass Spencer at 2.30 pm and decide to head for Berowra Waters. It’s off our track but at least we’ll have a peaceful night.

On passing Bar Point I realise that we have broken the back of the trip. I feel a great sense of accomplishment. The Hawkesbury is a green coloured river and we are very close to navigating its length in the green Mothership. Unless I can be proven wrong, I’m going to assume this as a World First.

What makes this an amazing boat was that we are able to do this and then talk about it around the dining table at night, steak on the BBQ, a glass of cool wine and ice cream for dessert.

Oops forgot about the sit-ups.

Berowra Waters 23/12/14 – Day 4

Overcast and intermittent rain. Not the best day for solar powered boating. But in spite of the weather conditions we are still charging. 5 amps into the house batteries at 12v and 3 amps into the motor batteries at 128v. Just a trickle into the motor batteries because we are just topping up, the batteries are nearly full. Having had such a good day yesterday we decide to head into the marina at Berowra to empty our grey and black water tanks and take on a little fresh water.

Berowra Waters is an idyllic spot. It’s a steep flooded valley. The houses cling to the waters edge, many only accessible by boat. Quietly we make our way but I’m aware of the straining necks of locals eating breakfast as we pass by. The Mothership does turn a few heads.

Poppy and Jamie enjoy their independence. They head off fishing in the rubber duck. We try to keep an eye on them but eventually loose sight. We know they have fallen behind us exploring fishing spots but are not exactly sure where. A strong headwind is developing and with it some tall waves. Although the rubber duck is faster than us but in these conditions it can be wet, uncomfortable and even a little dangerous. “If not duffers won’t drown”. Sure enough after a couple of hours they speed home having hugged the shore line. Out of our line of site but also out of the worst of the weather. Clever girls.

With the girls on board we head off through Milsons passage, under the Brooklyn bridge and passed Dangar Island. On passing Brooklyn we say goodbye to Jamie who catches the train home. It’s been nice having her on board. Our onward destination is Americas Bay where we will spend Christmas Eve and Christmas Day before we head round to Pittwater on Boxing Day, the end of our journey and the end of the Solar Challenge.

Technical Stuff
In spite of the poor weather I never had to go near the diesel genset. The weather did perk up a little which gave us a little more energy. At the end of the day and with just under 20 nautical miles covered we had used only 20% of the battery bank.

Americas Bay Christmas Eve – Day 5

Sometimes it’s nice to do not a lot, Sue took a landing party for a walk ashore – I got on with a couple of little jobs, taking my time and enjoying a beer. Early evening and in the spirit of Christmas we invited a few people from nearby boats to have a drink on the Mothership. I like impromptu. It was a really pleasant evening and certainly put us in a good frame of mind for Christmas Day.

Americas Bay Christmas Day – Day 6

Our little tree served us well. All around the country Dad’s are opening their carefully wrapped socks, I did well this year with 12 pairs. The others did well too. Sam got an Arduino board, Leo got Lego and Poppy watercolours. India got a magic spoon from her mum and Sue now smells very nice. After breakfast we had a tootle around and ended up in Jerusalem Bay. We couldn’t find Bethlehem bay. The kids went to jump off the rock, about 15 metres high, there were the usual squeals and shrieks. India had to be coaxed down – Sam and Poppy sang to her not sure what they sung but it must have been a very long song because she was standing on the edge for a good while. On their return the told us about the hammer head shark they had seen. A meter long apparently.

We enjoyed Christmas Dinner. Turkey of course. It’s just fabulous having the whole family around a dining table on a boat.

I know what they say about eating and drinking and swimming in shark infested water but after coffee I decided it was my turn to jump off the rock. I swam the 300m over to the rock and climbed up. It is a long way down at low tide. I knew that if I flinched I would loose my status of chief nut case in the Knox family. I jumped. Boy the pain. I think my legs we are little bent forward and the water smacked me on the bum with huge force. Apparently sharks can smell fear. The fear was gone but replace with pain. I limped back to the boat with a side stroke hauled myself up. Then I declared it all a bit boring really compare to the cliffs in Mexico. What a man. We wandered back to Americas bay where we spent the night. It was a night of the dark and stormy variety but we felt snug and safe and after such a big day we all slept well.

Americas Bay Boxing Day – Day 7

Are we world record holders? For the moment, yes. We hold the record for the First and Fastest voyage down the Hawkesbury River in a solar powered craft. However, I wasn’t allowed to get “up myself” as we say here in Australia. We needed bacon so Poppy, Sam and India headed off to the convenience store in Palm Beach. I picked up what I thought was a mooring. A few minutes later a fisherman speeded over. “It’s not a mooring you dickhead” he proclaimed “it’s a fish trap”. Oops.

We motored on to Mooring bay and had a celebratory breakfast. Unfortunately I missed a radio interview with 2GB. Mobile reception is not always the best in picturesque coves good for breakfasting. Then as my ship mates tidied up I motored past Scotland Island and down to Bayview. I didn’t hold back and pushed along at a good speed. We arrived in Bayview a little after 10am. The home straight, well not exactly because we don’t live in Bayview but it is the end of our Solar Challenge and unless I can be proven wrong a “World First”. That is Windsor to Bay View on Solar alone.

I was up early as I wanted to get around West Head before the breeze picked up. West Head can be nasty and although I’ve done over 200 miles at sea in the Mothership there are rules. Namely, respect every wave, be cautious and turn back if it’s not safe. I let go the mooring at a little after 6.30am and headed east towards the heads. The sky was mostly blue and we were picking up a little charge but at this time in the morning with the sun so low in the sky it wasn’t enough. We dipped into our batteries which is what they are there for. The Mothership pitched as we hit the swell. It is both a good and a strange feeling having been on flat waters for much of the week. Up she went then down she went. Her motors at half speed give a slight low pitched rumble, it’s more the noise of the prop-shaft and propeller but it is very reassuring. As we turned into Pittwater the pitching turned into rolling which eased off very quickly. We’d done it.

The sun shone, I couldn’t stop smiling and like the guy who gets to the summit. I looked around and turned the Mothership 180 degrees and headed back. SOC (state of charge) 65% SOM (state of mind) 100%.