Dog life vest recommendations

I have a 45lb Aussie going on a year old that I’m looking to rig up for the water. He’s denser than a rock (literally and metaphorically) and I’ve gone thru 3 generic life vests that he can’t seem to get comfortable in.
Anyone have any good high quality vests for floatation for furballs that’s better than the generic Petco/amazon varieties? Looking for something not so bulky so he’s comfortable laying down in the back of the kayak. Looking to spend some money to get a good one.

I had a Shepard mix that is as you decribed.  about the same weight and dimensions.  she loved to swim.

we got her a RuffWear PFD.  it fit fine.  she could lay down.  they sold them at a Feed store nearby so we took her in and fit her into one.

great handle on top to hork her back onto the dock, or out of a swimming pool.  I Never took her on a SUP or kayak or boat. 

I think REI carries the brand???  maybe

I second the Ruffwear. Mabel (45-50 lbs)rocks a medium in safety yellow and is totally comfortable in it. She swims fine without but you never know what can happen and the handle and short leash are frequently used to bring her on board.