Float Bags increase weight capacity?

Hello. I’m looking to increase the weight capacity of my sit on kayak and saw that people say float bags stuffed inside the hull are an option. I usually carry a cooler on the stern storage area of my kayak and even though that I’m well within the weight limit of the kayak the stern still seems to ride pretty low on the water. Any suggestions would be greatly appreciated!

A float bag in the hull will help with keeping you afloat by not allowing that space to fill with water if swamped but it will not increase weight capacity. You would only really be adding the weight of the bag itself to your total capacity.
You also can’t always bank on manufacturers weight capacities being spot on.


If filled with helium.


Weigh capacity is based on the amount of water displaced. Adding float bags inside or on a deck does nothing, as it does not displace any additional water. As Oldboo said, float bags are useful at displacing water in a flooded boat, which can bee an added safety measure.

It sounds more like a balance issue than a capacity issue. Too much weight on the stern. Can you switch to a lighter cooler? Or use 2 smaller coolers and place one at front and one at back?

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Around here many people add DIY pontoons to the stern of their SOT fishing kayaks for stability and to add more capacity to that end of the boat.

Do a picture search on google of SOT kayak DIY pontoons and you will see loads of photos and links of how to do it instructions.

I’m surprised the kayak manufactures haven’t picked up on this trend and built them as a purchase option.

Yes I’m thinking about moving a soft insulated dry bag cooler to the front in one of the dry hatches and that should distribute weight better. I think the seating being more rearward in the kayak than it is centered may also be a problem.

I am just going to go into more detail here about the role of float bags.

Float bags exist only to take up space in the kayak that would already be filled with air. For this reason, they do not add any flotation to the boat than was already there. What they do is take up space that might otherwise fill with water (due to a leak, capsize, or failed hatch/cockpit cover/skirt).

So, no, the only way to add flotation is to add it to the outside of the boat (there are products for this, but I won’t mention them and potentially activate a sleeping troll).

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The answer is they do not.

Even adding floatation to the outside of the boat will not add capacity unless it is added below the water line. Canoes often have sponsons just below the gunwales and their function is not to increase the load rating of the boat. They are there more for preventing the canoe from tipping over and in the event you do get it to go over it will have enough buoyancy in the sides when being righted to be flipped back in deep water without scooping and filling with water. Bow and stern float bags will keep a swamped boat higher in the water and possibly avoid it being pinned they aid some in righting a swamped boat and have the potential for reentry and being high enough to bail. IMO side bags or sponsons are preferable but in a solo boat there is not the space most of the time for side bags. Sponsons make the boat wider and can also catch on things you may want to slide away from.

I think most paddlers don’t have a clear understanding of floatation and things like sponsons.