my first thought is why are you in a no light penetration without a line . . .
Well . . .such is the Truk Lagoon Wrecks planning dilemma:
Especially for the GUE Cave and UTD Wreck-trained Divers as to overhead protocol: you will either be with a dive guide who will lead your team on traverses through the shipwrecks' cargo holds, superstructures & engine rooms etc. --all without running line-- or choose to run a reel-line & egress out on reel-line without using a leading dive guide.
The advantage of running a reel-line is of course safety & standard operating overhead procedure as trained; the disadvantage is that you won't have as much bottom time to fully & efficiently explore the wreck than if you did a through-and-through traverse. In other words, the dilemma will be whether to do "
Trust-Me" dives with a Dive Guide or not. . .
The Trust-Me Dive goes both ways in Truk --the Guide is vetting you on the initial easy shallower checkout dives, making sure of your general trim & kicking technique as well as your aptitude & temperament for wreck diving. He's gotta be sure that you won't panic when the rust & silt starts "percolating" all around you, far inside an engine room at 51meters depth. . .
There will be times where you will be in a tight engine or crew space in a near silt-out or "Black Hole Cavern" as described above; or momentarily lose sight of the Guide around a corner corridor or up through a vertical gangway (especially a disorienting vertical passageway in a capsized ship that was once a lateral corridor of 12 meters length or more -IOW, you might have to counterintuitivly
descend 12 meters or more to egress the hull/superstructure);
You have to trust that the Guide knows where you are at all times as well as all wreck egress pathways, and the Guide has to know that you won't make a potential lost diver contingency worse by freaking out. . .
A compromise best solution is to have a "Pathfinder Team" --that is a team laying line with a Dive Guide in front leading a traverse through the wreck; and then having other teams come in later following that line to video/take pictures/sight see artifacts etc. --and then finally later a "Clean-Up Team" to reel-in the guideline, while traversing back in the opposite direction and winding-up reel-line. . .