MARK C I am 6'2"270. I use the 2X and it is extremely comfortable. I have always used Scubapro Stab Jackets since 1979, Mostly Classics, But did try the Nighthawk, did not care for that, and returned to the classic. I used the Seahawk last year, and fell in L.O.V.E., Awesome BC, and very comfortable. Hope this helps...MC

NEIL D I am 5'10" and 190lbs. I have a medium and it is very comfortable even with a 7/8 semidry with 3mm core warmer. Also use it with a 3mm and 7mm wetsuit and it is great. I would go a size up for you.

JAMES G I am more or less the same size, and wear a 3mm wetsuit or just a rash guard. I bought the XL Sea Hawk and wish I had bought the Large. The shoulder straps come on easy when putting a full tank on from the ground which is a plus, but the cumberbun and buckle are way too big. Even after tightening the cumberbun from the back, I barely get enough velcro to fasten and the buckle is always loose fitting. Also when shore diving I tend to sink into the bc during swims. I don't have experience with drysuits but this is my experience after 20+ dives with the XL. Hope it helps

DAN V I would assume any knife would fit, I never use a dive knife. Since I purchased this BC for my wife she does not use one either. I have been using Scuba Pro products for 20 years and in my opinion you can't go wrong. Diver Dan

MARK C I have loved and used Scubapro equipment since the 1970s I have always used the stab jacket, except my spare for travel was a glide pro. I tried the Seahawk and have to be honest, I love this BC and probably will never go back to the classic which is now my spare...Now to answer your question. The knife grommets are the only terribly poorly designed thing i can find. As it happens I am a dive knife collector, and always wear two larger knives than the current (i think foolish) mini dive knife craze. I wear two midsize oceanmaster titanium knives. To utilize the grommet system I took a 5 inch piece of plastic board drilled holes in it, put it behind the grommets and ran plastic ties out through the grommets and mounted my oceanmaster sideways so can use it with either hand, its out of the way, and still allows the weight pocket to hold its weights, it rides on top of the pocket and i can still access the zippered pocket next to the knife. I can also add larger knives if I want, Just have to use new plastic zip ties. This is my spare knife. Any cutting etc i have to do I use the one in a knife pocket on my right thigh. I do alot of wreck diving and just always wear two. If the engineer who designed the grommets had half a brain, there would be two small grommets an inch or two apart, and another set 4-5 inches away it would make life easier, but most BC knife grommets are similar to the scubapro ones. It looks great and as stated is out of the way, and of course with titanium, no real maintanense worries. Hope this helps. I made the plastic backing by purchasing a cheap white cutting board from the sporting goods section at a walmart, cut the piece to fit, sanded it smooth, rounded the edges and it fits perfectly, will not break, and securely holds the knife with the electrition grade plastic ties, a little hassle maneuvering the ties inside and out the grommet but it looks good..Hope this helps...

DERRICK B Standard grommet/D-ring that can hold any knife with a large hole to scecure to your BC. You have the option to place on an outside d-ring or inside your pocket. Excellent back inflate BC and your knife can be placed just about anywhere including on you.

DERRICK B Buy a medium. If you predict that you will gain about 50 pounds over the next 10 years, get a large. I purchased a large, weight 190, 5 11" tall and have to tighten every buckle down for it to fit properly. Amazing BC I must say!!!

HERBERT C Well, I'm 6' and 250 lbs and the XL is almost a bit big. My Dad is 5'9" and around 160 lbs and my Seahawk is WAY to big for him. I'd go with a medium since they straps are have pleny of extra to accomodate you. Heck, I could have probably gone with a Large instead but I seem to get rounder the older I get...

DAN V Purchased a large, check ScubaPro site for lift on medium and small sizes. I can tell you the BC is simply the best on the market. My previous BC was a ScubaPro, I had it for 15 years with no issues and I still have it. Even though the Seahawk is weight integrated, I still utilize my old style weight belt with one exception....I use two one pound weights in the back stablizing pockets. The ScubaPro is an A+ BC

Ben T If you drysuit dive go 2x if not xl is fine.

JOSHUA S I am 6' 190 lbs and I wear a large it fits good with just a rash guard or a 5mm wetsuit if that helps any