Is a 8.5' sit-on-top kayak good enough for near shore ocean?

Both of my tandems have that same design, with the scupper hole under the seat. I usually plug those, unless it's a warm water trip. They both have other scuppers too, and usually don't plug those ones.

Most sporting goods stores have basic scupper plugs, think I got some at Big 5 for like $8 for 4. Good to measure before you buy, different brands have different sized scupper holes.

I used Dollar store cat toys like a squishy ball for a while on my first non-hobie   

I used Dollar store cat toys like a squishy ball for a while on my first non-hobie 

Haha, I used a pool noodle wrapped in electrical tape until I realized I could just get some at Big 5.