Introduction: Wooden Floor for a Seahawk 4 Fishing Raft

Apartment life has its perks, weekends free from yard work and unexpected home repairs, But one thing most apartments lack is storage space for fun weekend things like canoes. Kayaks are small but not very 4 year old friendly.
This is how I was introduced to world of inflatable boats. I was hesitant at first but ultimately after being realistic about what we would be doing in the craft, lake exploring / lazy river floating and fishing for $100 what did I have to lose.

Step 1: Getting to Know the Seahawk 4

Once getting the raft home and inflating it I was impressed by the thickness of the 30 gauge PVC sidewalls of this thing. I would not want to hit class 3 rapids in it but it did not feel like a pool toy either. I was also taken by the size of this raft the dimensions on the box nearly 12ft long and just under 5 ft wide. Be sure to use the inflation gauge that comes with the raft it is easy to over inflate this is a common cause of issues in inflatable boats.
On the water with 2 adults and 1 child the raft was quite stable but as would be expected it doesn't track or paddle like a hard body boat. But this raft can float in less than 1ft of water and is quite manuverable.

After the fun filled maiden voyage I had three things to improve on: The oars that come with the boat are bit short and I plan to replace these. I have an idea to use the rafts motor mount lugs to attach a skag to help with tracking. The final area and first project was installing a wooden floor for better stability.

Even though the floor mod is a popular one for this raft I had a hard time finding any good construction info or details.

Step 2: Inflate, Measure, Cut

After fully inflating the 3 chambers of the raft measurements were taken of the underside of the floor chamber. I am not posting every test fit and trim etc the dimension pic above is the final used dimensions after test fitting. If you spit the floor into 3 sections as i did to minimize storage space remove 2 inches from the center panel length. If you are making a 1 piece floor the measurements shown should work fine.
I used 3/8 plywood sheet this was ok but I feel 1/2 would have been a better choice after testing on the water.

Step 3: Sand Edges and Trim

After getting the floor cut sand the edges to prevent splintering. I used 1/2 foam pipe insulation (the kind you can find at any hardware store for $0.99 a stick) to pad the edges. Drill a parameter of holes 1" inside of the outside edge of the panel. The holes should be placed about 6" apart for cord or wire ties to lash the insulation to the edges.
I've seen staples used for this but pointy objects and inflatable things don't get along. Plus after use the foam will pull through the staples and have to be reattached.

Be sure to do a test fit with the edge covering before carpet covering. Also be sure to add a hole in the rear to access the floor chamber filling valve.

Step 4: Cover With Outdoor or Auto Grade Carpet

I covered both sides of my floor panels with automotive carpet. It can usually be found in 6ft x 8ft pieces and this was perfect for project.

The basic idea is to lap the bottom side of the carpet over the edges and staple on the top side of the panel then the top cover is cut to the edges and stapled over the overlap. This will ensure all staples are on the top surface. If they start to back out you can see this right away in stead of being hidden underneath. I kept all staples as close to the board edge as possible so that the once the pipe edging was attached it too would cover / protect the boat from loose staples.

Step 5: Test Fit and Finish Up

If creating a sectional floor Completely cover and trim the bow and stern sections. Place these in the raft and test for the center section. This is when I realized the center would need ~2" taken from the length. Once all is fit correctly cover and trim the center section and enjoy your new robust floor.

Step 6: Final Notes

The biggest plus to this project is the cost to fun ratio. I had to purchase all the materials for the floor upgrade which was around $35. Altogether including the cost of the raft I spent less than $150 for a portable rec. boat.

One could go all out adding seats and decks but then you would be in hard side boat money or you could buy a professional grade pack raft that will be rated for extreme rapids and made of ballistic material.

Comments

author
CsabaF5 made it! (author)2017-08-07

Thanks for the dimensions!

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НенадС2 (author)2017-03-23

I m interested inicial dimensions of the flood

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ToddS2016 (author)2016-09-07

Thanks syfrog! Is anyone else finding these measurements are too large? It seems like they will put a lot of pressure on the outer chambers. My measurements were more like 88" x 27 to 27.5". Comments? Experiences?

(also, I'm modifying this design by adding two hinges and some tie-down slits so it will double as a roof rack carrier for the boat)

author
syfrog (author)ToddS20162016-10-28

It is possable there are some manufacturing differances between newer rafts???

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ToddS2016 (author)2016-09-11

Update: Out on the water the plywood floorboard seems to push the floor air chambers down more than in my shop, so some space appeared, but even after adjusting my initial measurements to 93"x28" it's still really tight until you get into the water, unable to add foam bumpers on land. It seems possible, just concerned about putting too much pressure at the seam of the floor/sidewall air chambers...

author
ToddS2016 (author)2016-09-08

Update: after my boat was inflated for a few days I was able to inflate it more and I'm starting to get measurements closer to yours. Also I found out the pump I bought was not strong enough so that's another reason the boat was not fully inflated. I'm still not at your full measurements but getting closer. I hope this helps the discussion...

author
phlynch3. (author)2016-07-20

thanks a lot. just struggling a bit on the radius measurements. I see an X dimension, but don't I need a Y dimension to find the origin of the center to run the Radius curve. I must be missing something. For the 1.25" and 2.8" radius, you give an X dimension from center but no Y dimension. For the lower 3" radius, no dimension, but I assume this could be found by finding the origin that is tangent to both the vertical and horizontal edge. thanks for any help

author
syfrog (author)2016-06-25

Looks good! Nice work.

author
burkdog24 made it! (author)2016-06-20

It's done!

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burkdog24 (author)2016-06-20

Do you like having the seahawk 4 floor inflated or deflated with the wood floors ? I would think that the floors would be more stable deflated, but not sure.

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plesperance (author)2016-04-04

I wonder if it would be possible to use old pallet's. I have the seahawk 3 but I simply don't have a way to transport such a large piece of wood to and from the lake the main reason I use inflatables is because they fold up and fit nicely in my bicycle trailer. If it was poisbile to use pallets that essiantally can be broken down and fit together like a puzzle then I could make a wooden floor for it, but I don't think it would work unless someone has an idea that would allow for such a design.

author
RachelM131 (author)plesperance2016-06-17

i saw someone made a hard floor and just cut it in half for easy transport and storage, brilliant idea. They used plywood i believe

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syfrog (author)2015-08-07

I still pump my floor when using the wooden floor, that is also why I placed the access hole in the rear corner to get to the inner chamber valve.

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Perrunchin (author)syfrog2015-08-20

Great, thank you for the response! I'll post pictures once mine is done.

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Perrunchin (author)2015-08-05

Hi. Thanks so much for the Instructable. I have an Intex Excursion 4 and I will be following your guide to make a wooden floor. I just have one question. Does the inner chamber where the wooden floor rests need to be inflated or you left that one deflated when in the water? From all the mods I've seen I haven't been able to figure that one out yet.

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garg11 (author)2015-06-10

That is impressive!

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EthanBeltramo (author)2015-05-09

deme sins were perfect!

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syfrog (author)2015-02-26

Sounds like you had fun! Thanks for sharing your pics.

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joropeza herrera made it! (author)2015-01-25

Thanks Syfrog, excellent explanation, i did this in around 8 hours, it is my first time working with wood, so i had to learn how to use a jigsaw, i had to learn how to sand it, and upholstery.. that one is new too lol, i spent around $45 in miami using 1/2 waterproof plywood i finished today at 2 pm and went straight to fish with my wife, daughter and 2 friends, also im building a custom made battery box, so it will be my first instructable!

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author
syfrog (author)2014-10-20

Glad to help.
Thanks for the pics.
Great job, your boat looks sweet!

author
fwmmeister (author)2014-10-19

thank you so much.... sizes are right on wide-wise.... the length is a bit too long if you use the insulation as cushion.... I took a 1/2" plywood and camouflage fabric.... thanks again....

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syfrog (author)2014-08-25

The pic is not the greatest should be ~2.8". Thanks for the catch.

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craig.pumphrey (author)2014-08-17

hey quick question, the top left number on your diagram is that 28" that doesnt seem right, so im guessing im miss understanding or miss reading,. thanks :)

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syfrog (author)2014-07-12

Sweet! Glad this helped.

author
rpetrovich (author)2014-07-02

Thanks for the dimensions, fit like a glove and saved a boat load of time (harhar)

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