I am trying to comprehend why a dive op would limit bottom time (within reason). One of my lsd’s has a 45 minute max bottom time on one of the double dive charters ( costs over $100). That is ridiculous. I would spend way more time checking/packing/driving and washing my gear that actually diving. If the schedule is tight, start earlier (often best conditions early) If I look for a dive op and there website says unlimited dive time I will sign up every time. A lesson to any dive operators let the people dive their tank!