For about ten years I snorkelled the way most visitors do — rented mask from a kiosk, half an hour in the water, mild enjoyment, back to the beach.
Three changes turned it into something I now organise trips around, and none of them cost much.
The mask is the whole thing
Rented masks are the reason most people have a mediocre time and do not know it.
A mask that does not fit leaks, continuously, and you spend the swim clearing it rather than looking at anything. Rental stock is generic, heavily used, and the seals perish.
Fit is individual and testable in about five seconds. Hold the mask to your face without the strap, breathe in gently through your nose, and let go. A mask that fits stays on by suction alone. One that does not, falls.
Buying my own, fitted that way, was the single biggest improvement. It cost less than three days of rental.
The second thing is that new masks fog persistently because of a manufacturing residue, and need cleaning before first use. Toothpaste rubbed on the inside and rinsed works. Without that, a new mask fogs constantly and people assume it is faulty.
Breathing, which nobody teaches
The second change and it sounds too simple to matter.
Most beginners breathe shallowly and quickly through the snorkel, because the tube adds resistance and because floating face down is mildly unnerving at first.
Shallow fast breathing does not clear the tube properly, which means you re-breathe your own exhaled air, which makes you feel short of breath, which makes you breathe faster.
Slow deep breaths, deliberately, fix this entirely. It takes a few minutes of conscious effort and then becomes automatic.
The related point is relaxation. Tense swimmers use far more energy, get cold faster, and cannot stay in as long. Floating still and letting the water do the work is the skill.
Where and when, which matters more than gear
The third change was realising that most of my mediocre swims were in the wrong place at the wrong time.
Visibility is everything and it varies enormously. Rain runoff, swell, wind and tide all reduce it, sometimes dramatically. The same spot can be superb one morning and useless the next afternoon.
Morning is generally better than afternoon, because the wind is usually lighter and the water has had the night to settle.
Sheltered bays hold visibility better than exposed shores.
And the days after heavy rain are frequently poor everywhere, because everything the land washes out ends up in the water.
Asking somebody local where to go today, rather than where is good generally, gets a much better answer.
The safety part
Snorkelling looks benign and has real hazards, and the fatalities that occur mostly involve a few specific situations.
Going alone, which is the most common factor. Snorkelling with somebody who is actually paying attention to you, rather than nearby doing their own thing, is the basic precaution.
Currents, which are hard to perceive when you are face down and absorbed. Checking your position against a landmark regularly is a habit worth building, because it is very easy to drift a long way without noticing.
Cold, which creeps up because you are not moving much. Being cold impairs judgement before it feels serious.
And boat traffic, which is the reason for a bright float or buoy in any area where boats operate. A snorkeller is close to invisible from a boat.
What I carry now
My own mask, fitted properly.
A snorkel, which matters much less than the mask, and a simple one is fine.
Fins, which I resisted for a long time and which make a large difference to how far you can go and how little energy it takes.
A thin rash vest or wetsuit top, which extends how long I can stay in by a factor of two or three and also solves the sunburn on the back that everybody gets exactly once.
And a float, in anywhere with boats.
What changed about the trips
I now choose destinations partly for what is in the water, which I never did before, and I plan the days around morning conditions.
The difference between a decent snorkel and a good one is not the location's reputation. It is the fit of the mask, the time of day, and whether you can relax enough to stay in for an hour instead of twenty minutes.
All three of those are within anybody's control and none of them appear in the descriptions of where to go.
Not touching things
Worth stating because it is easy to do harm without intending any.
Coral is a living animal and contact damages it, including standing on it, which people do when they get tired and look for somewhere to rest.
Some sunscreens have been implicated in reef damage and several places now restrict them. Covering up with a rash vest instead is both cheaper and avoids the question.
And picking things up, including shells that may be occupied, is generally illegal in protected areas and is a poor habit anywhere.