Regarding the negative entry ....Whether Florida or Asia or NJ or UK.... Ocean sites :
- are water --water is the same everywhere
- either Low or No current
- Or medium to high current
- have just one dominant current
- Have a top current, a mid depth current in a different direction, and a bottom current.
- Have either a bare desert like floor of sand, and one Wreck --like an Oasis in the desert
- Or there is a large reef area to be hit anyway you like
- Or there are specific structures that require some precision in descent to reach.
If I left out anything, someone should add it here....
For low or no current, the line is not required by the negative entry style I like, because the captain marks the wreck below with the fathometer ( and is at the gps location), and when he has determined that there is no drift, or that he is in the right place to have a diver on top of the wreck, he drops us....even in 5 foot vis, this will work on wrecks as deep as 100 feet easily....on 220 foot deep and deeper, it is only going to work if there is no current or low current, or if the ship is very large...This thread is NOT about tech drops though, so this is irrelevant.
For high current, a diver is not strong enough to pull down the line without extreme difficulty--and when it is really fast, a diver is incapable of pulling down the line--this is an issue that will not change between Florida, UK, Asia, or anywhere else. If anything, a warm water destination can run slightly faster for the line, as thin and slick wetsuits will not be grabbed as much by the current, so divers here can tolerate a little more as they work their way down or up. Fort Lauderdale florida, say 30 miles from WPB sites, is an area where they typically run an anchor and use ascent descent lines for wrecks. This is a place I have experienced first hand, that many divers can not pull down a line on days when the current is ripping "for Lauderdale"...the thing is, Lauderdale on a high current day--is a very mild current or medium at worst, by Palm Beach norms.... When divers can't handle the current on the line ( a DM will try first if the current seems close to the limit of diver ability--the captain will have a good sense of this to, from how the boat is on the anchor) .. These same wrecks are easy for Palm Beach operators to drop on regardless of current, and some of the captains in Lauderdale have Palm Beach drift experience, and they change to drift mode when conditions and diver requests dictate. The issue here, is that the captains BEST at delivering perfect drift drops, do this in Palm beach every day.....The captains in Lauderdale that get a job in Palm Beach, usually take some weeks of training before they get the skill of estimating the drops perfected.
If there are top, middle and bottom current variations, most of the Palm Beach Captains will have trouble with this on bad vis days and 80ft or deeper....( which usually is a deeper dive phenomenon anyway)
So we used Lauderdale for many deep wrecks in the 90's, and this was a place where on some days vis could be 10 feet to 20, even though it can run to 60 or 100.....and on the low vis days, the norm was lines to hit the wrecks. But we found some Captains skilled in Palm Beach Style drops, and our team would hit these wrecks with far more gas than the other divers that would go to the same wreck and fight hard all the way down to a 200 to 280 foot deep wreck...often these poor guys were being spun around like a fishing lure on the descent line , and there arms were filling with lactic acid, there breathing at close to an Aerobic pace on a bike.....We would be down 5 to 10 minutes before them, and reach the wreck at a heart rate of around 65 or below for some of us. Clearly this is an exageration of the issues on a 120 foot deep wreck, but everyone has this in common--we all want as much extra reserve gas for our chosen dive as possible, we want the longest time on the wreck itself as we can have( no wasted time if possible), and we don't want to chance getting a major muscle workout on ascent, as this has
major DCS ramifications, as offgassing is poor with heavily contracted muscles and cramping--which happens to the line using divers on the higher current days where they can still manage to go up and down on a line. Again, the drift drop eliminates the DCS issue from drastically reduced offgassing potential from fatigued muscles.
Where there are a series of structures that could interfere with a hot drop....Not because of the drop itself, but with the idea of towing a float the whole time......the alternative in "some cases" could be dropping without the float deployed, staying on the primary structure as long as desired, and on leaving the structure, deploying the inflatable torpedo float from depth....once beyond the structure...and then continuing the dive.
If the current was so strong that there is a fear the divers could not descend into the drop point, it would be my contention it is too strong to pull down on a line.
I can easily demonstrate a line technique on one of our Jupiter Wrecks, versus a hot drop...on a day with a good current, the big red ball floats are immediately sunk by current....and even when it is not strong enough to sink them, the current is going to turn the diver into a fishing lure, spinning around almost helplessly, and making themself a DCS wannabe

We used to do this stuff--with lines, and got tired of the issues....this was in the 80's....Frank was the one that solved this, the other boats did lines....After a few years in the early 80's, the ONLY boat I wanted to dive from was on Franks, due to the ease of his drift drop technique....and by the mid-80's, pretty much all the Palm Beach boats used hot drops for wrecks unless a group requested a line.
Boynton would get away with using lines on some of it's wrecks, for divers that preferred this, as the current is much more mild in Boynton Beach...it was a place you could do either--though we always found drift dropping the easier way by far....But the boats would let a group use whichever method they want--unless the current was ripping--meaning it would be pointless to do a line descent--so the choice then would either be a hot drop, or abort that site, and find a long reef where a slow descent without line, or with the line on a big red ball could happen.