Boat maintenance with help from the cat

Fudge inspects the pontoons of Seahorse
Fudge inspects the pontoons of Seahorse

Boat maintenance is always assisted by one of the cats these days. Sometimes they stay out of the way, but if there are any moving parts in evidence I can be sure that a little paw and some whiskers will intrude on my handiwork before long.

Ship’s cat

Mini shows her best figurehead pose
Mini shows her best figurehead pose

Mini came to live with us to be a friend to Fudge. She is immensely curious, performs routine inspections of the entire house on a daily basis, and likes nothing better than to explore the back of my car and inside the boat. Here she demonstrates that she’d make a fine figurehead, posed on the bow of our rubber duck, Seahorse.

Mini has a change of heart
Mini has a change of heart

Later she realises that the life of a ship’s (boat’s?) cat is not as easy as it may seem when the boat is trailered in the driveway…

Supporting Romeo’s Wish

This year, Learn to Dive Today has donated a Discover Scuba Diving experience as a prize in the Romeo’s Wish raffle, to raise funds for DARG (Domestic Animal Rescue Group) in Hout Bay. We love dogs and cats (all creatures except mosquitoes, actually!) and are happy to contribute towards making a difference in the lives of some pets that would otherwise be neglected.

You can read more about Romeo’s Wish here, here and here. Details on how to buy a ticket for the raffle are below:

Romeo's Wish

Dive gear maintenance: Masks

Masks tend to fog up due to some form of contaminant on the glass. You are told when you buy a new mask to give it a toothpaste treatment, or “burn it gently with a lighter.” These theories have dubious origins and the reality is that the glass is dirty: silicones from manufacture, sunscreen, and natural body fluids all make the glass oily.

The Number Two cat has some opinions about dive mask maintenance
The Number Two cat has some opinions about dive mask maintenance

The trick is to wash the mask with warm soapy water. End of story, a clean piece of glass will not fog up. Baby shampoo is often recommended due to the fact that if you leave a residue in the mask it wont burn your eyes, but after years and years of experimenting and testing all the different suggestions I can assure you warm soapy water works like a charm.

I wash everything with Bio-Classic (an enzyme-based washing powder that is great for cleaning off body fluids) and this includes all my masks. I rinse them well after washing and store them in a plastic container.

Enriched Air/Nitrox Specialty

If you’re a Cape Town diver, and serious about enjoying the huge range of wrecks and reefs we have here, there are two Specialties that you should seriously consider.

One is the Deep Specialty, which qualifies you to go to 40 metres. (The depth it qualifies you to go to is actually less important than the skills you will learn on the course.)

The Number One cat helps Tony apply a Nitrox sticker to one of his cylinders
The Number One cat helps Tony apply a Nitrox sticker to one of his cylinders

The other is the Enriched Air/Nitrox Specialty. Enriched air is ordinary air that has been enriched with extra oxygen. This reduces the nitrogen concentration, which is a good thing for two reasons.

  1. When we breathe air under pressure, nitrogen is absorbed by our body tissues (particularly quickly by fat). While you’re at depth this isn’t a problem, but it becomes a problem when you ascend too fast and neglect to do the required safety stops or decompression stops. The nitrogen forms bubbles in your blood, brain and joints, and you will get bent. This can be fatal, and it’s a horrible way to go. You can think about what enriched air does for you in two ways: you get extended bottom time within the no-decompression limits, or a margin of safety because if you follow the dive tables for air when breathing nitrox, you will have absorbed less nitrogen into your tissues by the time you ascend. The risk of decompression sickness is thus reduced.
  2. Nitrogen has a narcotic effect when breathed under pressure, and this can impair judgment and lead to all sorts of stupidity on a dive. Less nitrogen in the mix you’re breathing means less narcosis.

It’s not as simple as just putting more oxygen in your cylinder and jumping into the water, however. Oxygen is toxic when breathed under pressure (you just can’t win!) and can cause convulsions. At the bottom of the ocean, a convulsion is bad news. So while you are free to add oxygen to your breathing mix, your maximum depth is restricted by the richness of the mix you choose. Nitrox mixes are referred to according to the percentage of oxygen in the mix. Normal air has 21% oxygen: Nitrox 32 means that the cylinder has 32% oxygen in it.

The Nitrox Specialty is mainly theory – there are some formulas that you need to get to grips with, and you need to understand the two-edged sword that is enriched air. Once you’ve mastered the theory, you’ll learn how to use a Nitrox analyser, and probably do two dives on Nitrox.

As you dive more and more, your air consumption gets better and better. When you get to the point where your dives are limited by the no-decompression limits of air rather than the amount of air in your cylinder, the Nitrox specialty becomes extremely attractive. If you’re in the group of divers (such as older, or overweight) who are most at risk of decompression sickness, diving on Nitrox is a huge investment in your own safety. And finally, if you do repetitive dives (several dives in a day), diving on Nitrox will extend your total bottom time tremendously.

Bookshelf: Dolphin Island

Dolphin Island – Arthur C. Clarke

I loved this book so much that at the age of twelve, I named my cat, a magnificent ginger and white giant, “Clarke” after the author. Yes, I was a little nerd. I was given the book for Christmas by my parents in 1989, when I was eleven years old. The following year I did a book report on it for school – I found the cue cards inside the book when I opened it to re-read for this review.

My cue cards for my book report
My cue cards for my book report

Arthur C. Clarke is best known for his science fiction books for adults, most notably 2001: A Space Odyssey, which was filmed, and Rendezvous with Rama. He was a keen diver and futurist, and spent much time diving off Australia and Ceylon (where he later made his home) during his lifetime.

Dolphin Island
Dolphin Island

Dolphin Island is a children’s book, set in 2010 (which, at the time of publication in 1963, seemed quite far in the future but not so far that life would be impossibly different from the way it is now). It was written during Clarke’s convalescence from a near-fatal accident, and he states in the afterword that he wrote the book “as a conscious farewell to the sea” – which fortunately turned out to be premature, as he did much more diving after his recovery.

The novel concerns the sixteen year old Johnny Clinton, who stows away on a hovership (an amphibious cargo vehicle of the future) and ends up – through the assistance of a pod of dolphins – on an island off Australia’s Great Barrier Reef. There he meets Professor Kazan and his research team, who are engaged in research of dolphin language and communication. He befriends Mick, an island boy who teaches him to skin dive on the reef surrounding the island. After some time living among the islanders and assisting with dolphin research, hurricane forces Johnny to use his resourcefulness and courage to save his friend the professor’s life.

Unfortunately the book has been out of print for ages and I can’t find an active link for the book for online purchase, but you can find a used copy on Amazon.

The biter

The Biter was a cheeklined wrasse whom we encountered while diving in the Lagoon Tank at uShaka Marine World in Durban earlier in October. He caused great amusement to both me and Tony because of his persistent camera-hogging activities, suspicious-looking face, and willingness to nibble on exposed body parts.

The Biter
The Biter makes an appearance

He actually reminded me very much of the Number Two Cat (so-called for her place in the hierarchy of Tony’s neighbour’s 17 cats), who likes to stick her nose in your face at every opportunity to make sure that she’s still centre of attention.

Hello Number Two Cat!
Hello Number Two Cat!

But the Biter is a fish…

Being checked out by his red eye
Being checked out by his red eye
Making investigations
Making preliminary investigations
Coming closer...
Coming closer...
Open wide!
Open wide!

Here’s a rough edit of some of the clips Tony took of him. Notice how he tries to bite my finger (at this point Tony laughs through his regulator), and how he picks up a rock the size of a cherry from the tank floor, and appears to swallow it (I didnt see it come out, and I was watching). During parts of the clip he was so close to the lens that the camera couldn’t focus! The other sounds you can hear on the clip are bubbles, and the autofocus of Tony’s camera.

[youtube=http://www.youtube.com/watch?v=Vr&w=540l-Xtyh_JY]

Ode to the logbook

I am a numbers person. I love to record things, analyse trends, draw graphs, and notice patterns in data. For this reason, I’m totally obsessive about filling in my dive logbook. Apart from making me happy to record all that information, and filling a wonderful hour or two after each dive looking up what I’ve just seen in the pile of books on sea life that Tony and I have amassed between us, it has had some other, unexpected benefits:

  • I’ve been able to track my progress as a diver with respect to air consumption. When I look back at early dives, I feel proud about how much longer I can stay down with the experience I’ve built.
  • I can track my progress as a diver with respect to buoyancy and lack thereof – when I started diving, the dive centre loaded me with 12 kilograms of weight, including cylinder weights. I sank like a lead cannonball. With Tony’s help, we’ve reduced my weight to somewhere between six and nine kilograms (depending on how many wetsuits I am wearing and how much custard has been consumed in the recent past).
  • I can look back on different gear configurations, and see what worked in order to reproduce successful ones: how much weight I wore and where (on my weight belt or as integrated weights or as cylinder weights), how many layers of neoprene were donned, how large my cylinder was, and so on.
  • Regional information is useful. When planning our annual houseboating trip this year, I was able to look back on the water temperature from when we dived in Knysna in 2009, and decide how many layers of wetsuit I would need.
  • Seasonal information on fish life (what appears when – for example, giant short-tailed sting rays visit Long Beach in summer), water temperatures and general conditions is useful and interesting. Now that I’ve been diving for over a year, I’m delighted to start noticing the different patterns of life… what time of year we see lots of juvenile fish, when there are lots of egg ribbons at Long Beach, how visibility correlates with water temperature, when the shaggy sea hares are out in force, and more.
  • We like exploring, and have on occasion dived forgotten sites or even places that aren’t recognised dive sites as such, but we’re curious to see what’s there. Recording dive information and what we saw makes it easy to tell others about these sites, and to assist when we decide whether they’re worth visiting again.
  • The bucket list aspect is also fun. Tony and I want to try and dive as many of the dive sites listed on Peter Southwood’s Wikivoyage site for the Cape Peninsula and False Bay as possible. Recording the dives in my logbook is like ticking the places off on a list!
The Number Two Cat understands the importance of keeping a logbook
The Number Two Cat understands the importance of keeping a logbook

Many people start a logbook as students on their Open Water course, and then lose interest. Don’t give it up – aside from these personal benefits, your logbook will be useful in at least two other situations involving other people:

  • If you go diving or want to rent gear somewhere other than where you learned to dive, or with new people (for example a club), you may be asked for your logbook (as well as your certification card). The club or dive centre may want to verify that you have the experience to handle the dives you have signed up for. If you’re certified with a lesser-known agency, your logbook can also help persuade the dive centre that you know what you’re doing.
  • For certain PADI courses you need a minimum number of logged dives (for example, 60 for Divemaster and 100 for Instructor). If you don’t have a record of the dives you’ve done, it complicates matters somewhat!