An inflatable raft can sometimes be useful: Many years ago (long before kayaks) when I was younger, stronger, lighter (by ~40 lbs) and poorer, I used a rubber raft a number of times. While visiting relatives in Sarasota (FL) a time or two while out of class for the summer quarter, I would head down to Venice with my dive gear and a military surplus 4-man "rubber raft" I got from an Air Force buddy in a trade.
I inflated it with a tank dedicated to that purpose, hauled it down to the surf at the public beach, loaded my spare tank (sometimes two), suited up with gear for the first dive and swim out past the swimming boundary pushing the raft. When over what I thought might be a spot to dive I would drop a small anchor. The raft had a mount that displayed a flag.
This arrangement had a number of advantages---
It saved energy (and time) as holding on to the raft while swimming was much easier than just swimming out with gear and if the surf was a bit ruff it saved the air that would otherwise have been used swimming out along the bottom.
Having an extra tank saved the time (and again the air) comming back to shore to swap tanks.
Going out side of the swimming area boundary, the raft (with flag) presented a much better display for passing boaters.
If vis was reduced, not all that uncommon down there, you could work along with the small anchor, as even with a tank or two in the raft it was easy to pull along.
It comes in very handy if you find a larger item---like one time I found the ball from a ball and socket joint, probably of mammoth or mastodon origin, which was as big as a soccer ball---I simply surfaced and placed it in the raft.
Drinks and snacks could be on board, and it provided a resting place, if you were tired from a fighting a current.
I can think of a few more, but those should illustrate the point.
FLRiverDiver