wow I would be delighted if someone offered me that bet
Well I may actually feel guilty because it is so easy in reasonably warm water.
How did you get to have that bet?
The whole trick with freediving is relaxing and going slow.
Equalisation:
The thing you need to learn is to equalise head down with little air.
On your way down you need to keep your head in line with your body (not looking down to the target) and equalise elegantly every second.
Often people only equalise when they feel pressure on their ears, but this is too late.
In your case you cannot afford to skip 1 equalisation.
Duck-dive:
If you're overweight an efficient duck-dive is essential, it helps you under the first 2-3 yards, and avoids the stress inducing struggle at the surface.
Training:
If you can train for this in a pool do it, do some underwater swimming with fins, assuming you're wearing small fins, it means you need to make small strokes with a higher frequency. As you swim look down, not ahead, it reduces drag by about 60%.
Preparation:
As a preparation, you need to use some slow breathing to slow your (racing heart) down (you can practice that at home too). Your last breath should be 1 slow deep breath out, followed by a slow from the belly up inhale. SLOW is important, freediving is a funny sport because one needs to be relaxed and slow down. Being fired up and hyper is detrimental.
Practice equalisation, first on land. The simplest is Valsava (the stuff scubadivers learn), pinch the nose and gently push a bit of air too your nose, until you feel/hear your ears 'pop'. Usually 1 ear goes easier. Having a clean airways, and less mucus forming, and practice helps A LOT. A good sleep and a hot shower in the morning an sniff down your throat all the mucus to clean up your sinuses and Eustachian tubes. This makes equalisation much better.
Getting a local trainer/buddy.
However the best thing you can do is team up with a local freediver/spearo, and spend a few hours with him, and give him a percentage of the winnings would be nice in combination with your story. He could also safety you.
Risks:
- Foggy mask / leaking -> disorientation -> fear -> panic (huge O2 consumption with zero efficiency) -> Black out.
- Equalisation block/ reverse block -> eardrum stretch/ breaking -> vertigo (disorientation)-> panic (huge O2 consumption with zero efficiency) -> Black out.
- Low visibility water -> getting lost ->fear -> panic (huge O2 consumption with zero efficiency) -> Black out -> safety diver cannot find you within 1 minute -> brain damage or death.
- Entanglement -> fear -> panic (huge O2 consumption with zero efficiency) -> Black out.
- Poisonous sea creatures from causing irritation to immobilisation.
- Current -> getting blown away or sucked down a water channel -> fear -> panic (huge O2 consumption with zero efficiency) -> Black out.
- Hyperventilation (breathing more air than normally) -> lowered CO2 increasing O2 consumption and delaying urge to breath past the point of fainting -> Black Out (faint) at the surface / BO during the dive -> (Without Skilled help) leads to Death.
- Collision -> disorientation -> fear -> panic (huge O2 consumption with zero efficiency) -> Black out.
- Hypothermia -> cramps / High O2 consumption/ inability to relax, breath, equalise
- Dehydration -> cramps/ less O2 reserves -> BO
You see there is an extensive list of the risks, most of them you can prevent by not diving or learning the skills
Staying cool and collected focussing on what you CAN DO helps to stay in a functional state of mind.
To have a safe attempt try to arrange for this environment:
- Skilled in water safety diver, who knows how to find and bring people up from 30+ft and revive a person from a BO and do CPR, preferable knows how to administer O2. Such diver can swim along easily and secure and film your dive with sports camera.
- Clear waters
- Daytime
- No current
- No snorkel
- above a flat sand bed.
- White easy to grab Guidance rope going down vertically, with big buoy or boat so you can pull up and hold.
- Being skilled in equalisation, duck diving, relaxing, finning.
- Having a rescue evacuation plan (fast boat and quickly into ambulance to hospital, charged phones!)
The thing is, if I had 1 day with you, and your sinuses and ears cooperated, you would have a blast going down to 30 ft (+!) in a very short time, with easy and loads of enjoyment. I know some persons who should loose weight, but in the water they transform in the most elegant graceful divers, who easily cruise down and up to 120 ft, with no traces of exertion or exhaustion.
Find a local buddy and discover this great liberating feeling of freediving, maybe this bet will give you more then a 1000usd.
Love and Courage,
Kars