Thu, 2 April 2020

Surf forecasting turns to Coronavirus forecasting. The man behind Wavescape's surf report algorithm tells Spike why we need to wear masks to flatten the Covid-19 curve.


TURNING POINT: Masks are gaining ground as a key preventative tool against Covid-19.

Now before you jump up and down in righteous indignation because health workers need medical-grade masks, and don't waste them on the 99% of people who don't have the virus, we're talking about home-made masks made out of T-shirts or buffs or even underpants, not the N95 health mask so desparately in need by health professionals around the world.

"But its in direct contravention of the WHO recommendations!" you hear the Vleisboekers wail and gnash. "Masks make you fidget!" "Masks make you touch your face." "You spread the virus more with a mask!" "Masks make you worse than Freddie Krueger!"

Well, Pieter Streicher, PhD in Engineering, is here to tell us different. Piet, who is an avid windsurfer and surfer, has launched a #tshirtfacemask campaign to get us to wear home-made masks. His point is that the well-intentioned attempt to ensure adequate safety precautions - and enough face mask stock - for health workers has clouded the issue that short stints with masks in public spaces for the general public could be a crucial way to beat Covid-19.


COVID-19 SCENARIOS: Piet Streicher has modelled the novel Coronavirus curve in South Africa

denise-mwaniki-7ZGbAKNZdnA-unsplashPiet has been working on a mathematical model for the Covid-19 curve, with emphasis on South Africa. Surf forecasting has turned to Coronavirus forecasting - it was his genius that built the surf report algorithm I use on Wavescape. He extrapolated my anecdotal notes on 30 or so popular South African surf spots in different types of conditions, and turned them into maths.

The result were surprisingly accurate, individual forecasts for surf breaks, even those that face the opposite direction of the prevailing swell direction, such as Supertubes. There are some spots that are a bit inaccurate based more on the lack of science on my side. However, they retain value for surfers due to this trend. The consistency of the inaccuracy becomes an aid to forecasting the surf there, if that makes sense.

Now Piet has put his maths skills into modelling the novel Coronavirus, and has come up with interesting observations, including a correlation between masks and countries with lower Covid-19 figures. Of course, the data is prone to unknowns. For example, he warns South Africans against complacency at the recent slow-down in new infection statistics.

"We might be behind with tests, we might only be testing the already sick, or only the very rich that can pay for tests even when they are only mildly sick. I would not put all my faith in this apparent slowdown."

Over to you Piet:

The spread of the Covid-19 virus will slow down considerably if everyone wears home-made face masks when going out in public or when caring for a potential Covid-19 positive relative in a household. home-made face masks will prevent asymptomatic and pre-symptomatic people from spreading droplets containing the virus. When you speak, there are always droplets coming out of your mouth (Cohen, 2020).

This intervention was implemented by the Czech Republic since 18 March 2020 and should be followed closely. This measure should not replace other physical distancing, hand washing, isolation or lockdown measures.

There are several misconceptions concerning face masks amongst the public and the media that might put everyone at higher risk. Some of these misconceptions are well intended in that they aim to maximise the availability of medical masks for medical personnel. Then there is the observation that non-medical people do not know how to wear and handle face masks, putting themselves at higher risk. These factors result in the public being actively discouraged to wear all types of masks. This is a fatal mistake.

By limiting medical face masks to the exclusive use by medical personnel, the availability problem is addressed.

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FIND A FACE MASK: Or make it. As long as you understand how to manage them. Photo Unsplash

While non-medical people currently do not know how to wear and handle home-made face masks, they can learn to do so. We will soon have a situation where an increasing number of non-medical people would have to care for Covid-19 positive individuals in their households and the skilling up of everyone in the best practices is imperative.

The primary benefit of wearing a home-made facemask is the protection of others. The secondary benefit is the protection of yourself. My mask protects you, your mask protects me. Advising that masks should only be worn by those with the virus is not helpful, as you might not know if you are infected or not because the virus spreads while people are asymptomatic.

We should all consider the possibility that we might already be infected, but are not showing any symptoms, and that we might actively be infecting others (Pueyo, 2020). Not only when you cough or sneeze, but simply when you are talking there are always droplets coming out of your mouth. These droplets then contaminate all surfaces they land on.


VIRAL WARFARE: Asian countries with a culture of masks seem to be beating Covid-19. Unsplash

People are most likely to contract the virus by touching a contaminated surface and then touching their face. For this reason, people are well-advised to regularly wash their hands. However, each person should consider the likelihood of touching potentially contaminated surfaces when going out in public and then inadvertently touching their faces. Any barrier between your hands and your face will have a benefit according to David Price (2020), an ICU Pulmonologist currently actively treating Covid-19 patients.

Contracting the virus from the air is possible but unlikely. Normal medical masks would not protect against airborne viruses either, and in hospitals with Covid-19 cases, only personnel performing procedures such as intubation or those who are in close contact with coughing patients are at risk of contracting the virus via the air, and they should wear N95 masks (Price, 2020). Wearing a home-made face mask and keeping a two-meter physical distance from others in public is effective in slowing down contamination.

Hong Kong, Singapore, Japan and Taiwan have all been able to contain the virus. In all these countries, people have been wearing face masks for weeks now (Myburgh, 2020). The public Covid-19 posters in Hong Kong prominently display the use of face masks when in public. Taiwan is producing 10 million masks per workday. Taiwan does not have enough cases to appear on the graph below. This measure was not adopted in Italy, USA, Germany, Spain, France or South Africa. In fact, it was actively discouraged in the USA, UK and SA.


CORONA CURVE: Nations using masks are flattening the curve, according to John Hopkins University.

6-prevention in_workplaceThe Czech Republic made masks mandatory in public on 18 March 2020 (Euronews), and now more than a week later, they have a high level of compliance. This country needs to be monitored closely. As on 29 March, the known cases were growing at an average of 12% per day from 23-31 March. As on 31 March they had 3002 known Covid-19 cases and 25 deaths (death rate by known cases = 0.83 %).

The main reason masks have not been advocated for as a method to prevent contamination is that people have stockpiled masks, which has a detrimental effect for medical staff. Masks are critical to protect medical staff when treating infected patients. All members of the public that have access to medical masks should provide this to their nearest hospital. The general public should be encouraged to only wear home-made masks. In this way the supply of medical masks to medical staff will not be affected, while at the same time providing protection to the general public.

Above Right: A public poster in Hong Kong advocating the use of masks.

An obstacle to non-medical people wearing masks is that they do not know how to wear face masks, which puts them at higher risk. A medical expert recently said on South African radio that "as masks dampen with prolonged wear, they become quite good at conveying viral particles deposited onto their surfaces (both inside and out)."


CZECH SIGNS: Czech rules are that everyone must wear masks, and early signs are good.

"Also, based on observation, most people do not use masks effectively. They also tend to touch the mask more often, to adjust it or for eating and drinking, potentially depositing virus onto the surfaces. Consequently, the authority view is that members of the public should not use masks because they will derive no benefit from them. They may even increase their own risk. Therefore, masks out in public really aren't that helpful, unfortunately.

"You are right to highlight the dangers of transmission in a care setting. The close and prolonged contact that such care necessitates results in significant risk escalation. We estimate that 80% of transmissions occur in the household settings."

However, there is no reason why non-medical people can't learn the correct way to wear home-made masks. One way to practice to not touch your face would be to wear a home-made face mask at home (Price, 2020). The face mask will make you more aware of when you touch your face. This needs to be practiced long before you wear a home-made facemask in public, or long before you need to care for a Covid-19 patient in your household.


BE COOL: You can use one that goes with your outfit, but just wear it in public. Photo Unsplash

honey-yanibel-minaya-cruz-AnKgv6lV3oE-unsplashDuring the lockdown period, the intention is for you to only go out to buy food or medicine. This should be a short mission avoiding the prolonged wear risks. There should be no eating or drinking during this mission. When returning home, it must be assumed that the home-made mask is contaminated, and it must be washed immediately.

Masks can be made from variety of readily available materials. T-shirt material and pillowcase material have been shown to adequately filter droplets and has good breathability according to the scientific paper by Davies and others (2013). In poorer countries, where physical distancing is more difficult, everyone still has access to T-shirts.

Anyone can wear a T-shirt as a mask. A t-shirt head opening can be worn at eye level, with the sleeves tied behind the head. Make sure that you cover your chin with the mask.

There is a proliferation in DIY face mask solutions on the internet. When you go out, put on a clean home-made mask and focus on not touching your face. When arriving home, take off the mask and wash both your mask and your hands with soap and water.

Hospitals and medical staff absolutely need medical masks, and they are running out of masks quickly. This has resulted in a misleading message to the public, stating that face masks do not help the general public. While well-intended, this is not true. Below find a table with common misconceptions amongst the public, with suitable corrections.


james-jonathan-pUMvLj8TCbA-unsplashWhile there is a benefit to the individual wearing a home-made mask in public, one should really consider the benefit of everyone following this practice. If everyone follows this practice and everyone practices rigorous hand hygiene, fewer surfaces will be contaminated and the likelihood of hand to face contamination will be reduced. As more people follow this practice, the benefit will be compounded exponentially. This benefit should be modelled mathematically in the same way that lockdown measures were modelled in the article by Harry Stevens, 2020.

By making it compulsory for all to wear home-made masks in public and by creating awareness of proper mask wearing practices, the growth in Covid-19 infections will be slowed down dramatically, without putting medical staff at risk due to a shortage of medical masks. The Czech Republic introduced this practice on 18 March 2020, and the early signs are positive and need to be monitored closely. To ensure that medical staff have access to medical masks, the public should be encouraged to hand all medical masks over to hospitals.

home-made face masks are an affordable and effective way to limit the spread of Covid-19. Many people are asymptomatic and are actively spreading the virus simply by speaking. When you speak there are always droplets coming out of your mouth.

Be an example to others during lockdown, by publicising your home-made face masks on social media and encouraging others to do the same. By doing this, this habit could potentially spread faster than the virus itself.

My mask protects you, your mask protects me.


Cohen, J 2020. Not wearing masks to protect against coronavirus is a ‘big mistake,’ top Chinese scientist says. Sciencemag 27 March 2020

Davies, Anna & Thompson, Katy-Anne & Giri, Karthika & Kafatos, George & Walker, James & Bennett, Allan. (2013). Testing the Efficacy of home-made Masks: Would They Protect in an Influenza Pandemic? Disaster medicine and public health preparedness. 7. 413-418. 10.1017/dmp.2013.43

Euronews 24 March 2020. Coronavirus: Czechs facing up to COVID-19 crisis by making masks mandatory

FT analysis of John Hopkins University, CSSE, Worldometers; FT research.
Country by country: how coronavirus case trajectories compare

#Masks4all campaign

Myburg, James 2020. “The coming winter flood”

Pueyo, Tomas 2020. “Coronavirus: The Hammer and the Dance”

The Economist, How Long Can The Novel Coronavirus Survive on Surfaces and in the Air

Price, David 2020. Empowering and protecting your family during the Covid-19 pandemic (Video here)

Stevens, Harry 2020. Why outbreaks like coronavirus spread exponentially, and how to flatten the curve.


  • Before putting on a mask, clean hands with alcohol-based hand rub or soap and water.
  • Cover mouth and nose with mask and make sure there are no gaps between your face and the mask.
  • Avoid touching the mask while using it; if you do, clean your hands with alcohol-based hand rub or soap and water.
  • Replace the mask with a new one as soon as it is damp and do not re-use single-use masks.
  • To remove the mask: remove it from behind (do not touch the front of mask); discard immediately in a closed bin; clean hands with alcohol-based hand rub or soap and water.


Suspected COVID-19 cases who are medically well, or who are assessed as having only mild disease, may be managed at home while awaiting test results.
Such patients should be instructed to self-isolate at home and be given appropriate advice about reducing possible transmission to others:

  • At home, the patient should stay in a specific room and use his/her own bathroom (if possible). If they live in shared accommodation (university halls of residence or similar) with a communal kitchen, bathroom(s) and living area, they should stay in their room with the door closed, only coming out when necessary, wearing a facemask if they do so.-
  • Patients should avoid unnecessary travel and unnecessary contact with other people.
  • Where contact is unavoidable, the patient should wear a facemask, and maintain a distance of at least 1 metre (preferably 2 metres) from other people
  • Patients should clean their hands with soap and water frequently. Alcohol-based sanitizers may also be used, provided they contain at least 70% alcohol.
  • Make sure that shared spaces in the home have good air flow, such as by an opened window
  • Patients should practice good cough and sneeze hygiene, by using a tissue, and then immediately discarding the tissue in a lined trash can, followed by washing hands immediately.
  • Patients should not have visitors in their home. Only those who live in their home should be allowed to stay.
  • Patients should avoid sharing household items like dishes, cups, eating utensils and towels. After using any of these, the items should be thoroughly washed with soap and hot water.
  • All high-touch surfaces like table tops, counters, toilets, phones, computers, etc. should be appropriately and frequently cleaned.
  • If patients need to wash laundry at home before the results are available, then they should wash all laundry at the highest temperature compatible for the fabric using laundry detergent. This should be above 60° C. If possible, they should tumble dry and iron using the highest setting compatible with the fabric. Disposable gloves and a plastic apron should be used when handling soiled materials if possible and all surfaces and the area around the washing machine should be cleaned. Laundry should not be taken to a laundrette. The patient should wash his/her hands thoroughly with soap and water after handling dirty laundry (remove gloves first if used).
  • Patients should know who to call if they develop any worsening symptoms, so that they can be safely reassessed.

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