Category: Boys log

Introduction

Singapore Strait is one of the busiest shipping lanes in the world, and some of the biggest ships in the world use it! It is 105 km long and 16 km wide and around 2000 merchant ships go through it every day. A quarter of the worlds traded goods go through the Singapore Strait. The largest container ships in the world are about 400 m long and many of these go through the area.

Our AIS (Automatic Identification System) logs all the ships we meet in a 20-mile radius. We wanted to find out if:

• Cargo ships are bigger than tankers
• Longer ships are wider
• Wider ships have deeper draughts
• Smaller vessels travel faster
• Cargo ships travel faster than tankers
• There are more cargo ships than tankers.

Method

On 12 and 13 October 2019, we logged details from ships we met in the Singapore Strait for a period of 18 hours as we were sailing along. The things we logged were:

• MMSI number (maritime mobile service identity – the ship’s unique identifier code)
• Name
• Length
• Width
• Draught
• Speed
• Position
• Port of destination
• Time
• Type
• Status, underway or at anchor
• Latitude
• Longitude
• COG (course over ground)

We entered the data into an Excel spreadsheet where we analysed it for our boat school maths.

Results and discussion

We logged 132 ships in total, of which 18 were too far away to get the type (the AIS records more details as the ships come closer). 36 ships were heading to Singapore, and 18 to China. 16 were heading to places in Malaysia, some to Japan and some to Indonesia, as well as Australia, Taiwan, Thailand, Vietnam and Brunei.

The pie chart below shows the number of each type of vessel.

Overall, we saw more tankers than any other ships, although cargo ships came close. All the other types of ships were very scarce. This makes sense because Singapore Port is the busiest cargo port in the world and almost a third of the ships were going there, and some of the other ships might have come from there.

The next graph shows the length versus the width of the ships.

The ships increase in width as they increase in length. According to our data, the width of a ship is about 19 per cent of the length, although it does vary.

The graph below shows the relationships between the draught and the width.

We assumed that the wider the ship is the deeper the draught. Our data showed that it was generally true, but it varied quite a bit.

The longer the ship, the wider it is. The draught has to be bigger on the bigger ships otherwise the ship will not be weighed down.

The next graph shows speed versus length.

One of our hypotheses was that smaller vessels travelled faster than larger vessels. This was proven to be false. The two fastest ships were small, about 40 metres long, and were ferries.

We wanted to see if there was a difference in the speed of cargo ships and tankers. The next graph shows this.

We thought that cargo ships travel faster than tankers, and we were right: the maximum speed of cargo ships was higher than tankers, but the tankers’ median speed was higher.

Below is a box plot showing the length of different types of ships.

Our last assumption was that cargo ships were bigger than tankers. This one varied a lot, but cargo ships beat tankers by more than 50 m, in terms of their maximum. The largest ship was 400 metres, so it was one of the largest ships in the world! The smallest cargo ship was much smaller than the smallest tanker, and the range of sizes in cargo ships was much larger than tankers.

Nowadays ships are reaching their maximum size. Too much bigger than 400 metres and the ship will not fit under any bridges, not fit through any canals, be very restricted to move, and will not be able to go in places much shallower than 20 metres. For example, a ship over 320 metres long cannot go through the Panama Canal, and a ship deeper than twenty metres cannot go through the Suez Canal.

Conclusion

We saw a lot of ships but if we continued plotting, we would have found many more. Most were recorded during the night. To make it more fun we pretended we were blowing them up so we needed all their statistics to find the right bomb.

On the reefs of Indonesia, a war is brewing.

Mr Flatworm is looking for the secret entrance to the meeting room. He needs to participate in war plans against the snakes. “Ah found it!”

Nudie does not usually go to meetings but this one is important. The snakes are going to eat them and Nudie is a good negotiator. He has made a plan of where to put the defences over the reef.

Meanwhile, King Moray is making a sneak attack plan. Eels and snakes are on the same team. He is going to send two assassins to go to kill two different targets. One is Queen Leafy, the other is the humans, the slugs’ two most powerful allies.

“Must go warn Queen Leafy!”  says the Urchin Fish.

“Must go warn the humans!” says Frank. Sadly, Frank never knew the humans lived out of the water. He can’t go onto a boat, so the humans were never warned.

These tube worms are Evil Pit Monsters that are ready to eat slugs on a moment’s notice. They are in the deadly prisoner pit. Once the slugs are captured, they will be thrown in here.

Sneaky Snake gets ready to kill the humans that are his targets. They are on their command ship. Humans are huge and he is small but his poison can kill them.

In the secret meeting room everybody is restless. “Everybody calm down!” says King Glutton, who is the king of the sea hares.

“Uhh, this is not working.” He shouts: “ORDER IN COURT!”

Everybody is silent.

In the Leaf Head Palace, Queen Leafy is having some trouble. “Ahh! Go away,” she says to the Camouflaged Stalker. She knew she was being stalked but she hadn’t expected this!

“Never! I am here to kill you,” says Camouflaged Stalker.

“Die!” He lunges at Queen Leafy.

“I’ll save you!” shouts the jellyfish projectile fired by the slugs’ cannon. It smashes into the Camouflaged Stalker who swims away screaming: “It stings, it stings!”

On the humans’ command ship Sneaky Snake snuck along the top of the door but he slipped and fell on one of the human’s feet. The human shrieked and kicked him off. Suddenly a light was shining on him, he screamed “Ahhh! the light.” The humans plopped him into the sea.

“I’m scared,” says an innocent bystander, pretending to be a rock. He saw the slugs, Queen Leafy and the humans drive the snakes of the reef but he was still terrified.

“Ggggggooooooddddddbbbbbbbyyyyyyyeeeeeeee,” says the giant cuttlefish. Thanks for reading.

Impressions from Wakatobi

I have not had an idea of what to write about as we have been moving from city to atoll to reef to a dive resort, which is where we are now.

Last week, a Swedish boat with two 10 and 11-year-old girls and a 6-year-old boy invited us over for dinner. The kids didn’t speak much English so we played card games and pillow fights where Lukie attempted to suffocate me. When we arrived Mum and Dad got out of the dingy with Lukie. I was about to get out too when I noticed a moving rope on the petrol tank.

It was a sea snake! It slithered off the tank into the water at the bottom of the dingy. I picked it up and put it in the bailer. They are very poisonous but their mouths are so small that they can only bite the skin in between your fingers, so that’s why I didn’t hold it.

“What does it feel like Matias?” asked Lukie as I dropped it in the water.

“Like a sea snake,” I answered as I was getting out. It felt like a rough rubber hose.

The Swedish boat had bought a big trevally that we had for dinner after Lukie had decided I was not a soft toy that he could strangle. This also happened to be the first time I have tasted cuttlefish. A woman from another boat had brought a curry to the party. I ate the curry, it tasted good. Afterwards, my mum asked me if I liked the cuttlefish and I said:

“What cuttlefish?” The cuttlefish was in the curry.

The day after the dinner, I did a try dive with my mum. I had to put on my BCD, buoyancy compensation device, and roll backwards into the water from the dinghy. I was wearing my short wetsuit so as soon as I went down to 5 metres I was freezing.

The day after, me and my mum did another 2 dives, one in the morning and one in the afternoon. On both I was wearing a longer wet suit, but on the second when I went to 11 metres I was a bit cold.

Under the water were some bamboo platforms where we practised some skills like taking off my mask and recovering my regulator so I could get it back if it fell out of my mouth. We did a tour around the area and had a spade fish follow us around. When I waved my finger at it, it started to chase my finger until the last second where it turned away and started to do fishy things again.

We also saw some nudibranchs that we had never seen before.

I like diving because you get more time in the water than when snorkelling, so you can get a better look at things.

In the afternoon a local in a boat tried to sell us a fish. We already had some so we said no thanks. Then he offered us some crabs. They were half a foot long and still alive so we decided they could be dinner.

After thanking the local fisherman and giving him some money, we put them in a bag which we tied to the boat and dropped into the water. My Dad cooked them at lunch time, and at dinner I tried some. I am not a big fan of crab or crayfish, and I was not expecting it to be so cold. I would have liked them more if they were warm.

The day before yesterday I did my last dive. On the dive we did no skills and saw lots of sea snakes. When we got out Lukie said:

“Matias did you see all those sea snakes? One zoomed out from the water and nearly hit me!”

I nodded and unclipped my dive gear. Lukie asked my mum whether he could have a go so a second later he was under the water looking for more snakes.

Yesterday a local in a boat came up to us. He offered us a bucket of water. Inside were a bunch of lobster tails.

“Wait here,” I told him.

I went to Dad and said:

“A local want to sell us lobster tails.”

My dad looked puzzled and went to see.

“Ah, mantis shrimps!” he said.

I went inside to Mum. “What are manta shrimps?”

Mantis shrimps are fat shrimps the size of your foot with eyes and legs like a praying mantis, just only more scared-looking than evil-looking.

In the evening we had some other people over. Lukie and I were mainly playing in my room while they were there, and when they were leaving I asked: “What did we do with the mantis shrimp?”

“We had it for dinner, did you not get any?” my Dad said.

“Aw, I wanted some!” said Lukie, a little bit annoyed.

Apparently, it tasted like lobster.

Plastic in the ocean is a problem. While sailing around in Indonesia we have seen a lot of plastic on beaches and in the ocean.

Plastic in the sea is bad because fish die. They eat plastic because they think it is food. If they keep eating plastic, their bellies will get full because they cannot digest it. The fish will keep on eating because they are hungry, but they will have no space for any more food, and then the fish will starve. Plastic ropes and nets can tangle up animals like turtles and dolphins underwater, who will die because they will not be able to move to the surface to breathe.

We came up with an idea to collect data on how much plastic there was on an island called Pulau Leleve for our boat-schooling.

Pulau Leleve is a small island east of Halmahera in the Molucca region of Indonesia. Nobody lives on Pulau Leleve but fishermen visit it sometimes. It has a beautiful white beach and further up the shore perfect, shady, plastic-filled areas of shoreline for us to sample.

Our hypotheses were:

• There is more than 20 pieces of plastic per every 10 metres of shoreline.
• Every ten metres of shoreline there is more than a bucketful of plastic.
• We will find more plastic drinking bottles than any other category.
• Most plastic on the island is under thirty centimetres long.

Methods

We went to a beach and found a place to collect rubbish. We measured a 10 x 10 m square with a measuring tape above the high tide line. Then we gathered all the plastic and counted and sorted it into categories. The categories were:

• Drink bottles
• Other bottles
• Cups
• Shoes
• Styrofoam
• Bags
• Rope
• Fragments
• Ice lolly tubes
• Lighters

We weighed all the categories and estimated the total volume of plastic found using a 10-litre bucket. We then repeated the process in a different area.

For analysing the data, we put it into an Excel spreadsheet. We plotted some graphs and made some tables. We then measured the perimeter of the island on Offline Maps and used this to estimate the total amount of rubbish on the island.

Results

This graph shows the amount of plastic we collected in total. The most common type was plastic water bottles, followed by fragments, then styrofoam.

This graph shows how much the plastic weighs. We only found six shoes, but they weighed a lot.

This is a dot plot to compare how much the different types of plastic weighed and how many pieces there were. We found more water bottles in weight and number than any other category. Even though we had a lot of fragments and styrofoam they did not weigh a lot.

These tables shows how much plastic we estimate is on the entire island. If the amount of plastic we found is present everywhere, there will be close to 7000 bottles on that small island, weighing more than 225 kg! If this rate of waste keeps up there are soon going to be entire islands that are made of plastic.

We think there are 7 cubic meters of plastic on the island – that’s enough to fill more than 2 large family cars. In total we estimate there are more than 17,000 pieces of plastic, weighing more than 350 kg on this small island.

Discussion

Our hypothesis was that there would be more than 20 pieces of plastic per every 10 metres of shoreline. In fact, we found more than 120 pieces per 10 m – that is more than 6 times the amount we thought we would find!

Another hypothesis was that for every ten metres of shoreline there would be more than a bucketful of plastic. We found 5 bucketfuls.

We thought that there would be more drink bottles than any other type of plastic. In Area 1 there was more Styrofoam, but after adding Area 2 we had more drink bottles than any other category.

We also thought that most of the plastic would be under thirty centimetres long, and we were right again. The only plastic over thirty centimetres long was a piece of Styrofoam that was thirty-two centimetres.

We think this is a lot of rubbish to find in a small area. We reckon we probably missed out some because some bits would be too small and some could be buried under dirt and leaves.

If the plastic went into the ocean the fish and turtles in the area might die or go away. Boats might get their propellers stuck in plastic and the water will get full of microplastics.

We think the Indonesian government should ban some types of plastic that are used a lot, like water bottles. We also think the Indonesian people should be educated to stop throwing plastic on beaches and in the ocean.

 

We have left the rubbish-filled Port of Tual and we are heading to Namatote Island were apparently you can see whale sharks. We arrive in the afternoon with a Swiss boat called C’est Le Vent which is pronounced Say Le Vong in French.

Early in the morning we get up at about half past five to get ready to see the whale shark or hopefully sharks. Apparently, there are two babies (which are boys and each about six metres long) and a nine-metre female. The locals say females are hard to catch to tag.

After a big breakfast and a lolly from the Christmas calendar we zoom towards one of the fishing stations out in the bay. As we get closer, we see two fishermen throwing small fish in the in the water while another two wander around.

“Look! Look!” shouts Pierre from C’est Le Vent. A big spotty, black whale-looking thing slips right under the dinghies. Lukie slides in followed closely by my mum then me and Daddy. I get my camera out of the boat and start snapping away.

A six-metre whale shark sucks in water with small dead fish too. It was like a two-year-old. It spilt lots of fish and swam after other little fish (which were alive and swimming under him) and didn’t seem to notice us.

Dolphins also came in at one point to get some of the fish and the birds in the sky never really dived down. The shark swam under the fishing station and then we all started to talk.

“Wow!”, “That was big!”, “Moan!!!” That “moan” was not from us. The whale shark swam into the dingy rope!

It thrashed around spraying lots of water. Finally, it dived down again, we all thought it was gone, but no! It came back up chasing lots of fish that stayed just out of reach of its massive mouth. Just then a diving boat arrived, and the instructor told them to hop out.

We all climbed up onto the fishing station (which was called a bagan) and watched the divers descend under the six-meter baby. Up here the view of the whale shark was not obscured by the blurry water, so it looked cool. You could see the stripy and dotty white pattern snaking down its rigged back.

We left for Triton Bay the next morning. By the way, we called the whale shark Frank and went back to see him another day, he was so cool.

The last place before Port Moresby we have been was in the Louisiades and I got a lot of pictures from the amazing reefs. One coral bommie we went to had a tunnel going the whole way through and coming out on the other side and in the very middle. Inside the tunnels, there were bazillions and trillions of fish that were the size of my fingernail.

We went to a place in the Louisiades where we snorkelled a plane wreck. The plane was from world war 2 and it was shot down by the British. The plane was covered in coral and fish that like to bite you. I played with the biting fish a lot.

We are now in an Indonesian city called Tual. Most of the people on shore have never seen a white skinned person. When we went ashore people were taking pictures and selfies with me, Lukie and our friends from So What. We had a plan to charge them 5 dollars for a picture.