We have had a number of threads here about people who thought they were buddied with the DM, but didn't get the attention or assistance they expected a buddy would provide. It's not surprising, since the DM or guide is tasked with supervision of the whole group, so his attention is most definitely diluted.
In this case, if you were diving within arm's reach of the DM/buddy, then when you began to get light, you could have banged something on your tank, or even shouted through your regulator to get his attention and let him know you were unable to stay down. In addition, if you are sufficiently determined, you can swim down as much as five pounds of positive buoyancy (I know, because I lost a 5 lb weight on a dive once, and I was able to stay down at the end of the dive, albeit by dint of vigorous swimming). That might have given you a chance to notify your buddy, if you recognized the problem swiftly.
Overall, buddying with the DM is not a good strategy; but it sounds as though your other options in this case weren't great, either. I really feel for people who travel without buddies -- it has got to be constantly challenging to arrange something that's remotely comfortable, unless you can afford to hire your own DM for each dive.
In this case, if you were diving within arm's reach of the DM/buddy, then when you began to get light, you could have banged something on your tank, or even shouted through your regulator to get his attention and let him know you were unable to stay down. In addition, if you are sufficiently determined, you can swim down as much as five pounds of positive buoyancy (I know, because I lost a 5 lb weight on a dive once, and I was able to stay down at the end of the dive, albeit by dint of vigorous swimming). That might have given you a chance to notify your buddy, if you recognized the problem swiftly.
Overall, buddying with the DM is not a good strategy; but it sounds as though your other options in this case weren't great, either. I really feel for people who travel without buddies -- it has got to be constantly challenging to arrange something that's remotely comfortable, unless you can afford to hire your own DM for each dive.
