Sizing a Dive Rite Transpac 2

Hi all, I am looking to buy a Dive Rite Transpac 2.

My LDS can get one in for me, but only if I buy first (which means I need to choose size before trying it on). I have tried a lot of shops here, same story for all of them.

Does anyone have any tips on sizing a Transpac? I have seen this: TransPac, TransPlate,TravelPac, and VoyagerPac Sizing - Dive Gear Express and it seems that I would be either an XL or a L. Hard to be 100% certain.

I'm obviously concerned I will get the wrong size; I'm thinking too big may be better than too small. Any thoughts?

The DR Transpac is pretty good(forgiving) when it comes to adjustment. My LDS owner thought I should be in a large, even though the chart said XL. He called DR and they said, XL. That's what I have and it fits with plenty of room to spare. What am I saying? Unless you are on the borderline of L/XL, you will probably be fine with L. The shoulder to waist measurement is the most important. If your shoulder to waist is very close to 22" or over,then go XL. If not, you will fit into either one.

Cyp