In the past hard core wreck divers only did penetration progressively and did not use lines.
Basically, the cave community brought the use of penetration reels to the wreck community and it was not exactly love at first sight among wreckers who understood the value of getting to know each room or passage in a wreck well before progressing further. Part of it was also the fact that progressive penetration takes time and a large number of dives - limiting longer penetrations to the local zip code divers. Consequently it upset the social order somewhat when cave divers using cave penetration techniques were making significant penterations on their first dive on a wreck. In fact, there are some reports from early line using wreck divers of having the old hands cut their lines as "entanglement hazards".
Troubled history aside, there are benefits to each approach and they work well together. In some regards, there are significant advantages and disadvantages to lines in wrecks that do not apply as much to caves and vice versa. For example, lines often last for years in caves, particularly in little traveled side passages while that is not the case in wrecks filled with sharp edges, changing currents and rapidly decomposing structures, so permanent lines are not left in wrecks and you run your own continuous guideline each time - with no tees, gaps or jumps. On the other hand caves, despite the occasional breakdown or the more frequent silting and other "soft" changes related to flooding and river intrusion are comparatively static so it does not require quite as much frequency as a wreck to maintain a decent level of familiarity and permanent lines are normally laid and left in place.
In terms of learning a new cave, you can gather information from a map and from talking to other divers to acquire information that is not on the map (cave conditions, flow, silt, etc, where the lines is at, marked and unmarked jumps, gaps, etc.) You can also enter unfamiliar areas of a cave with a diver who has been there before and is familiar with it - the caution is to be sure that it does not become a "trust me" dive and that at no point in the dive you do not exceeed your ability to safely exit on your own or with the less exprienced remainder of your team if you get separated or if something goes wrong.
In practice, progressive penetration is something of a norm in cave diving with a prudent cave diver slowly building up experience in a system before pushing on to deeper and farther penetrations, even if in some cases only to the extent that you explore each end of a circuit or traverse before doing the entire circuit or traverse.
It does require situational awareness to note where the line is at, side passages, unique ties offs, potential line traps, navigational markers, and ideally times and pressures at the more significant landmarks or decision points so that if exiting in a silt out you can confirm you are exiting along the proper route and are never in doubt as to where you are, what you should encounter next and approximately when you should encounter it.
There is potentially some irony here as local zip code cave divers are the biggest beneficiaries of progressive penetration and are potentially annoyed and impacted by non local cave divers, many of them who are also wreck divers, some of whom show up and do significant penetrations in "local" caves without showing what is considered due regard and respect to the locals and upset the social order so to speak. What goes around usually comes around.
