If you are Scuba diving and then suffered from a heart attack, initially your body would sink to the bottom due to the diving equipment, the weighted belt, and other items. After death as your body starts to decompose it would bloat, filling up with gases, and depending upon how heavy the equipment and the weight belt that you were wearing, this would most likely cause your body to float partway to the surface, or fully to the surface depnding upon if the gases released by your decomposing body are sufficent enough to counteract the weight of any and all scuba equipment you are wearing or carrying.
There are many definitions of surface diving. The most common is to go from the surface and dive to the bottom. Some people think it is different.
Mantle
Jump to the bottom of the sea with a diving helmet
The correct spelling is snorkeling (shallow surface diving).
don't surface as much
You usually see them in diving competitions. The water spouting into the pool gives the divers perspective on the distance to the surface of the pool.
Only if that part of the bottom is within their diving capability, in other words if the bottom is not much deeper than 1,000 feet or so.
Snorkaling, diving, swimming and glass bottom boat tours.
Its farther from the surface where the sun reflects.
Water
No, but there are reduced bottom times compared to sea level diving due to the reduced pressure when you surface. Since ambient pressure is lower at altitude, a comparable nitrogen load will result in easier bubble formation in your body. The major certifying agencies offer courses in altitude diving. Get the course if you are planning to dive at altitude, or read their course books if you are just inquisitive.
With scuba diving, you are diving with an oxygen tank on your back and a regulator in your mouth. For SNUBA, there isn't an oxygen pack on your back, instead your oxygen supply is a long hose attached to a raft on the surface of the water.