Deni, the rising levels of nitorgen in the blood are the issue. I would check and see if you are pg at the time before you decide. I was in a similar situation - I was all set to dive White Island (a cool underwater volcano in NZ) when I was 6 weeks pg, so I had to give it a miss. If you stayed above 5 metres you should be ok though, because from memory the dive tables permit diving at that level for extended periods of time (nitrogen levels are low/negligible. I would err on the side of caution though, and maybe stick to snorkellng.

It sucks I know - this will be my third year of no diving due to pg or BF but it is sooooo worth it (BTW, I think you can dive when BF, but my boy was so tiny when summer came around that it was logistically too difficult to organise....)