10 years ago when we purchased our boat Kiko's motor, it was the logical choice. The Yamaha outboard Enduro in the two-stroke 200 horsepower version was the most popular outboard motor here on Roatan Island (even with it’s 16 gallon per hour fuel consumption), and there were thousands scattered about in various stages of disrepair. Being isolated away from mainland resources, and dealing with Central American supply chains, it behooved us to use a motor where there were plenty of parts lying around, and everybody's brother was an Enduro mechanic.
There comes a time for everything to end, and recently it became quite obvious that our long time trusted and true powerhouse of a 200 HP motor on our dive excursion boat Kiko was headed for the last roundup. With one salt-crusted foot on a banana peel, and another hovering its grave we decided it was time to retire the old gal, and seek a replacement.
Times and technologies march on, and four stroke outboards have come into their own as reliable, and their price had come down a bit, making them a viable option. They are quiet, powerful, heavier built, and have better (less) fuel consumption than 2 stroke motors of similar displacement.
We are now obligated as planetary citizens to do what we can to mitigate the environmental havoc upon whose chasm we find ourselves so precariously perched. We, at West End Divers side with, and support the 97% of climate scientists who all agree that carbon dioxide emissions are the cause of mankind's greatest threat to its existence by dramatically increasing global climate chaos. Watching the changes occur here on this coral fringed island first hand, we decided to stand up, and take on our obligation to our (and your) environment, and look into how much pollution the different models of outboard motors put out in the way of carbon related compounds.
The astonishing difference between the 2 stroke vs 4 stroke and diesel motors, is the amount of emissions given off in their exhausts. Touted as emitting 100 times more carbon monoxide (bad), and 300 times more hydrocarbons (so bad) as conventional 4 stroke motors of the same displacement (size) it's a wonder that you can see the boat through these colorless, and odorless gasses of doom. These gasses and un-burned fuel are discharged through the surface water as exhaust creating aquatic poisonous compounds of their own! But back to the atmosphere…
Hard numbers being well, hard to come by on exact horsepower to pollution comparison because of endless variable factors; age of motor, lubricants and fuel differences, power loads, stress level of the Captain, and even altitude can affect the quantities in emissions on a given motor. However, there is a determination where 1 scooter’s 2-stroke emissions can be compared to 30 to 50 taxi cabs.
A local scooter has a 100 cc motor
Our old 250 HP outboard had a 2600 cc motor
That's 26 scooters or 1040 taxicabs!
If you have ever driven on Roatan you are aware of the plethora of taxis. Untrained in their jobs, no concept of rules of the road or inclination of right of way, add an overdose of Central American machismo and competitive capitalism, and you would swear there re a thousand of them on this little island. There are a little under 500 licensed taxis on Roatan. One 200 HP 2-Stroke outboard puts out twice as much air pollution as all the taxis on Roatan.
It's shameful to think what we have done to the atmosphere in the past with this motor. Every trip to a dive site was like driving a thousand taxi cabs to the reef. I really regret our original purchase now, but we must move on, think purer thoughts, and point out that the creep next door has two of these environment destroyers on his boat. Some boats have been seen with 6 of these atmosphere killers working in an attempt at over compensation of an obvious inadequacy, dumping out the same pollution as 7000 taxis.
As responsible divers, aware of the impending environmental dangers to ourselves, our families, our way of life, and our very mortal existence on this planet, we are compelled, no I say, It is our duty to ask our dive provider “What sort of motor do you have on your boat?” Be discriminating, we only get one planet.
With our new 4 stroke Suzuki 150 horsepower outboard motor we have cut our emissions to the level of one taxi cab.