I recently did a PB 120 m dynamic with fins and have tons of questions. I did it in a 140m long pool in Mexico so there were no flip turns. I used Grafa 2000 freedive fins and a low volume mask. I have hairy legs and a dreadlock pony tail so not super hydrodynamic. My wife (and safety partner) timed my 120m swim at about 1 min 45 seconds . Also my best dryland static is (only) 4:30 as I have alot of troubles with having a higher heart rate for the first 2 minutes, sometimes it goes up over 100 bpm, then it falls to 40-50 for the last 2 minutes. So here are my questions: It seems weird that I can do 120 m and the world is 180 m, does it get really hard after say 150 m? It seems I am swimming much faster than others doing dynamic, is this true and is slower always better and would it help me? Others have written that when they do dynamics they get lots (maybe 6 or 8) of involuntary in-breaths (contractions) starting after only 1 minitue of swimming and during my dynamic I only got two very mild contractions right near the end, not the hard full blown contractions I get doing dryland static but only very mild throat gulping sort of contractions. I did not do any warm up swimming that morning and fasted from the night before. My breathe up is total 12 minutes sitting on edge of pool with 4 min slow relaxing breaths, 4 min of 4 count in breath, 8 count packing, and 4 count exhale, then 4 min of quick very deep breaths followed by last breath with full pack, maybe 15 gulps. Is this a reasonable breatheup? Also at the end I stopped because I "got scared" and "felt funny, like being all of a sudden paranoid", I didn't feel like I had to stop to breathe like I do when I do the static dryland apneas. I also didn't have any low Oxygen symptoms like stars in eyes or leg tingles or anything like that (and I have experienced these before in different open water deep feedives) and had very clean and easy exits. What do you think would have happened if I had kept swimming? Would I have gotten very hard contractions like in my static apneas, wouldl I have blacked out? Sorry if this is too long, I woud appreciate any tips, ideas, condemnations etc. Wes Lapp