This has meant researching just what happens to a body when it is immersed in the sea. I also have some inside gen on this as my husband was a fire fighter for many years and sadly has been involved in rescuing and fishing out bodies from the sea where we live.
So here you go...
Typically a body in the sea will usually sink and having sunk the body will remain that way until putrefactive gas formation decreases the gravity of the body and creates enough energy for it to rise to the surface and float. If the villain thinks he or she can get away with this by adding heavy clothing and/or weights to the body then they need to think again because although it will delay the body rising it will not prevent it. It could, of course, render the victim unrecognisable because the marine life will have made a meal of it, especially the soft tissue but then there could still be bone from which to extract DNA.
If the water temperature is consistently below 45 degrees Fahrenheit there may be no real decomposition even after several weeks.
And if persistently cold/freezing water there is just the possibility the body may not re-surface (so a let out clause for our killer).
Putrefaction proceeds at a slower rate in water than in air.
It is slower in sea water than in fresh water.
And slower in running water than stagnant water.
Depending on the water temperature and the type of water a body can resurface between 3- 14 days.
All useful information for a crime author and particularly for my Inspector Andy Horton crime novels and my Art Marvik mysteries.
I should leave you to read that particular Inspector Andy Horton novel but I won’t be that cruel. However, all I will say is that clothing can gather air and keep the victim afloat…
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