I was in a similar situation last year with my w daughters and I. We went to Cayman, but we got our own DM. It was our first saltwater dive as we did our OW in a midwest quarry. I was more money, but it help us greatly move thru the "first time with out your instructor" jitters. It also help the DM understand our limitations for the rest of the week. We did dive with the boat after that. But we also found Dive Op that went out with a 6 pack vice a cattle boat. I am very glad that is what we did. It allowed us to gain confidence in the skills that we learned and stay within our capabilities. We also had no peer pressure real or perceived to deal with as went forward. Air consumption was the one thing that we did impact others. We found that if we got ready quickly at the site so we didn't hold people up, and then waited to get in the water last, then first out we could minimize the mismatch in air and the impact on other. Once in the water our air was what it was and we dove to the rules we were taught or boat which ever was more controlling.
Our experience was that the divers we had with us recognized what we were (new divers) and that we earnestly trying not affect them and they were very supportive - generally the case with everyone I've met in the dive world.
Since then we've logged over 50 dives, finished our AOW and have been to Utila, USVI, and will be in Bonaire (with our LDS) this fall.
We are by no means "advanced" divers in the context of experts. But when we dive with people on the boat or the quarry that are where we were a year ago, we seek to be supportive, help if asked and we always tell ourselves that was us a year ago.
I didn't understand fully the concept of diving your skill and experience level when first OW, but go slow, be open with your DM and do not accept any pressure do things you are not comfortable doing.
My 2 cents for what it worth.
