Sending technical divers* into the often tight enclosed spaces of sunken ships is a very hazardous operation indeed. Tech divers are burdened with significantly more equipment that regular scuba divers, and currents/thermals in cold-water open oceans can be vicious, and the divers have to wear bulky dry suits, which not only hamper mobility but also are at risk of tearing on jagged metal or broken glass - and if a diver were to have his/her drysuit ripped open at 80m in the Baltic Sea, that diver would almost certainly die from hypothermia (a diver cannot simply shoot up to the surface after diving at that sort of depth: a series of safety stops (to minimise the chance of contracting deadly bends) would easily require up to 2 hours extra in the water in a graduated surfacing).
Another factor here is that bottom time for any diver at 80m would be 20 minutes at most - meaning that the divers would have had to rush and expend extra energy (something you never ever want to do when diving: the CO2 build-up can kill you) if they wanted to enter the wreck, manhandle a dead body through small gaps, exit the wreck, and start off towards the surface, all in that shortened period of time.
Yet another factor is a more gruesome one. After a couple of weeks in water - even cold water - a body starts accumulating decomposition gases in its abdomen and thorax. In an enclosed wreck, leaving the body with negative buoyancy. if the body is trapped within the wreck it would probably be especially difficult to extricate
I've scuba dived at 32m at Scapa Flow in Orkney, wearing a mandatory drysuit. I dived close to WWI wrecks, and the currents were fierce. I wouldn't have dreamt of putting myself in danger by actually entering a wreck, and no dive supervisor would suggest such an action. On the other hand, I've dived a WWII wreck at 31m off the coast of Sinai in the Red Sea, wearing nothing but a thin rash vest in effectively zero-current conditions, which allowed be literally to swim through the hold of the ship and view the lines of supplies (including motorbikes jeeps, and tons of ammunition) that were on their way to our army in North Africa before the ship was sunk by a German aircraft.
* Technical diving is any diving below around 38m depth: below that depth, the diver is forced to breath a special tri-mix of gases which is not available to regular scuba divers. And almost all tech divers use rebreather equipment, which allows them to optimise their oxygen usage by reusing unspent oxygen, but it's cumbersome equipment - all the more so when diving at 80m, because the divers would have to be carrying spare tanks of tri-mix and oxygen with them as well.
