You mentioned that Diver B had certified in warm water. If I can assume that means warm clear water then this was a major change in conditions.
Any entry level certification can only provide a limited range of experience in terms of conditions. Diving should initially be limited to conditions as good as, or better than, the conditions experienced in OW training. If a new diver forsees substantially less favorable conditions, additional training is advised. In this case, a pool review with a DM would have been helpful. Even more so if you could reasonably wear the same gear in the pool (especially exposure protection) that you would be using for the OW dive.
Your reaction was a good one. I have never seen a weight belt that cost more than an ambulance ride. Good job.
Any entry level certification can only provide a limited range of experience in terms of conditions. Diving should initially be limited to conditions as good as, or better than, the conditions experienced in OW training. If a new diver forsees substantially less favorable conditions, additional training is advised. In this case, a pool review with a DM would have been helpful. Even more so if you could reasonably wear the same gear in the pool (especially exposure protection) that you would be using for the OW dive.
Your reaction was a good one. I have never seen a weight belt that cost more than an ambulance ride. Good job.