How much weight capacity do you like to have between your personal body weight and the kayak's weight capacity?  I know this depends on how much gear one will carry, but I've never fished from a kayak and thus don't know how much I'd carry.  (Obviously I'd try to travel light).

What kind of kayak are you looking at? I think most of the sit on top fishing kayaks have weight capacities in the high 3 to 4 hundred pounds (some even higher). Mine's a 10ft sit in with a capacity of 325 but I'm usually around 200 when all is said and done with gear so it's not something I've ever thought about actually. If you're worried about extra gear tipping you over the weight limit I probably wouldn't stress about it. I carry more than I should but even then it's not that much weight wise. Most of it comes from my jig and soft plastics boxes. 

I have a Lure 13.5. The weight limit is something ridiculous like 450lb (IIRC).  I weigh around 200lbs and even packed out with gear, electronics, safety gear, and all of the camping gear I would need for a week, it still wouldn't come near the weight limit.  That said, paddling 450lbs would also probably suck. 

The one I'm looking at is not one of those big, large-capacity models.  I'm looking at one with a 275 lb capacity, and I'm 235 lbs.  I'm wondering if 40 lbs is enough leeway.  

Personally I'd be looking for a little bit bigger yak. 

 

The capacity of mine is 350...I weigh 200 and with all my gear I'd say I'm loaded to about 250. 

This article may assist you.  http://www.yakangler.com/blogs/on-the-line/item/3067-weight-capacity-explained  

 

3 hours ago, basscrusher said:

The one I'm looking at is not one of those big, large-capacity models.  I'm looking at one with a 275 lb capacity, and I'm 235 lbs.  I'm wondering if 40 lbs is enough leeway.  

 

I am am not an expert, so just speaking from experience.  Based on your size, mass, water displacement - whatever you want to call it; you are in need of something that has more weight bearing capacity.  Stability is the important thing that you will gain and what you are seeking, not the ability to lug more stuff to fish with.

 

Trust me, you do not want to find out the hard way by dumping your kayak and going for an unexpected swim.  Make sure to get a PFD as well and wear it, because the unexpected swim thing can happen in a blink of a eye, so there is no time to prepare for this as it's happening.   

 

Wishing you the best in your kayak search.

I think most of the decent kayak designed for fishing have a large capacity.  My kayak has a 400lb limit which is pretty good.  I'm 215 and probably have another 50 to 60 pounds of gear on it and have zero issues.  I have a Pelican Catch 120.

After doing a few demo days, watching someone exceed the weight capacity is hard to watch.  Paddling becomes a struggle, turning is a struggle, you can't stand, etc.  My preference is to have at least a 100# leeway.  You can load these things up, but they do not paddle as well when burdened.  This also where "seat time" comes in.  You want to try before you by.

5 hours ago, basscrusher said:

The one I'm looking at is not one of those big, large-capacity models.  I'm looking at one with a 275 lb capacity, and I'm 235 lbs.  I'm wondering if 40 lbs is enough leeway.  

I'm roughly the same weight as you are and paddle a kayak with the same specs. I try to keep it to a minimum of 20 lbs of gear and I don't take long trips either.

13 hours ago, jbw252 said:

This article may assist you.  http://www.yakangler.com/blogs/on-the-line/item/3067-weight-capacity-explained  

 

That article pretty much answered my question.  Thanks!