Interior, Flooring and other design choices 
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The Riviera as called out in the plans has a very simple interior. This provides many opportunities for creativity on the part of the builder.

The first step is to look over the Riviera / Monaco photos on the Glen-L web site as well as classic boat books. The second step is to assess how the boat will be used. Optimizing for cruising versus water sports will often lead to different interior layouts.

Based on this information you can make the first stylistic call. This the fundamental decision is whether you are going with:

Each one has its own set of trade-offs in style, where the effort is expended, and cost. For example, with any of the "finished" interior types little effort is required to be expended keeping the inside of the hull smooth and pretty when gluing up (other than for personal benefit) as it will be covered up. If you go with the open wood look, the interior of the hull IS the finished interior and every imperfection (in the cockpits at least) will show up.

One of the fundamental problems is deciding what to do about the floor boards. As you make the floor flatter, it will need to be raised to clear frame members and the stringers. The difference in height between a completely flat floor and a "reasonably flat floor" is about 6 inches (15cm). The completely flat floor places the floor at the same height as where the seat bottoms are shown in the plans. This leads to further modifications and design choices.

Test fitting and sitting

With the seating and control layout being a subjective thing, it is important to mock-up the interior using scrap materials to make sure that everything and everybody will fit comfortably. Changing seat height influences dashboard depth, steering wheel location and angle, throttle location, gauge position, etc. Changing the floor height impacts leg room which influences seating height, which influences dashboard depth, steering wheel location, ...

It is nice to test the seating, etc. in a closed shop. Just think of what the neighbors will say when they see the "crazy boat builder" sitting in the unfinished boat, holding onto an unconnected steering wheel. At least don't make any engine sounds as you do it! I hear that it IS common for home airplane builders to take photos of themselves sitting in the "cockpit" of the uncovered completed fuselage framework.

As part of the testing and fitting process, you should also consider storage options. Common storage locations are: bow area, under seats, alongside of the engine, and under the floor.

Under seat storage

If you make the bench seats narrower ( across the width of the boat) it may be possible to make them flip forward (like pontoon boat seats). This opens up storage possibilities. If you push the seat edges out to the sides of the hull, you may find that it is impossible to flip them up. Test fit them and tape on some throw able seat cushions to simulate the thickness of the final upholstered seats when testing the operation of any flipping / folding seats. Also do the flip-up testing with several people in the cockpit. What is workable with one person, may not be with 6 or 8 people on board.

In our boat the bench seats are basically fixed, removable for maintenance, but not convenient enough for most storage. We have the spare propeller mounted on the side of one of the stringers under the rear bench seat. The rear anchor is a folding design and it slides under the rear bench as well on the port side. The forward anchor is a mushroom type which fits nicely behind the driver's seat. The water intake and plumbing enters on the starboard side. Having the required access to the sea-cock / water intake valve makes storage on this side impractical.

The area behind the spotters seat (actually under the forward deck) is used for the front cockpit fire extinguisher and our "dry clothes" storage.

Under floor storage

Just face it, on this boat, under floor storage is really pretty impractical. In the forward cockpit, the floor boards are pretty well trapped under the seats. If the floor boards are made smaller so that they can be pulled up between the seats rather than forward, then additional bracing is required. The frames also limit how much length you have available for long items such as skis, paddles, wake or knee boards, etc.

We leave our boat in the water all summer. This coupled with the boat being used for water sports means that the bilge always has some water in it. The bilge pump will get the water down to ~ 3" (maybe having multiple pump locations would help) and we then have to manually bail and sponge out from then on. Of course if you haul out every time, then draining is easy. Anything left in the bilge water for an extended period of time will get slimy (another storage limitation). Also, any engine oil leaks or spills will coat the bilge and linger despite your best cleaning efforts. The oil does seem to have a preference for items left in the bilge vs. the hull. As a side note - be sure to check the clamp (or lack thereof) on the oil drain hose prior to engine installation!

The rear cockpit floor

In the rear center section between the stringers, there is some space left over that is not occupied by the exhaust and sea strainer. We use this for spare ski ropes and handles. Wherever you put your sea strainer and sea cock, make sure that they are easily accessible. It does not take much idling in duckweed to clog the strainer. In addition, most engine water pumps do not respond to intake resistance very well, so any increased resistance to water flow can lead to low cooling water pressure and possible engine over-heating. Hopefully, you should never need to access the seacock in an emergency, but it is very nice to have it easily visible, to ensure that the water is "on" prior to stating the engine. Ours is tucked under the rear seat and the position of the lever can normally only be felt (up = on, forward = off).

Rear floor with seat removed. The seat overhangs the brace (horizontal board on top of the stringers in bottom of photo) by about four inches.


In our boat, the outer portions of the rear floor are simply the inside of the hull. A "finished" raised section could be accommodated without losing much leg room and would also still be easily removed for cleaning.

This photo shows the center section with the panel removed. The floor panel rests on the mufflers and a vertical plywood bracket that extends upwards from one of the frame members. Note the notch in the plywood bracket for the drive shaft and packing to pass through.

The front of the floor panel ends at the rear of the transmission housing and this is also approximately where the exhaust angles down as well. Extending the floor up to the rear of the engine keeps body parts and ski ropes away from the drive shaft and coupling. Even if you delay the other floor boards (as we did) in an effort to get the boat in the water, this section is required.

Note also, the tops of the stringer clips are rounded over to make them more "foot friendly".



Front cockpit floor

The outer portions of the front cockpit floor are again simply the inside of the hull. Here the hull curvature, lack of access around the seats and limited leg room made floor-boards seem impractical.

Having a "finished" center section of the front cockpit floor is a necessity. The V-shape of the hull's center section makes for very unstable footing. The steering cable also passes through this area and should not be stepped and and is a trip hazard. The floor can be broken into reasonably sized sections that can easily be lifted or slid out. This is a time where test fitting around the mocked up seating is very important. It is easy to make the floor boards too big to be removed once the seats are in place.


Here are a couple of views the front floor. Again, the bench seat is removed to allow a better view. To remove the floor without removing the front two seats, the forward edge is lifted with the recessed lifting ring, and then slid forward. At that point it can be lifted out. There is really no way to lift it straight up without either narrowing the seats (very uncomfortable) or splitting it into two sections lengthwise, which would require more bracing. The piece running horizontally on top of the stringers is the forward support for the bench seat. It is screwed to the stringers and is unsupported at the outside (hull) ends.

The left photo is a view of the forward edge of the front floor between the seats. The board at the front edge is the top of the frame gusset. Note that in both photos, the floor is well below the top of the stringers. I did not want to simply lay the floor on the stingers as this would have sacrificed too much leg room. The recessed area in front of the floor is a great place to hold a cooler. It is easily accessible and not in the way of the driver or passengers. Forward from there, we normally carry spare life jackets and throwable seat cushions.

The right photo shows the rear section of the front floor after the floor board has been lifted out. It is held in place by 2 small aluminum clips in the rear that keep it from sliding back or jumping up. Simply tilt it up and it will clear the stringer mounting clips. Note, that if it were any longer, tilting to clear the stringer clips would not be possible as it would be obstructed by the bottom of the bench seat forward brace. The small amount of curvature of the clips is enough to keep the floor board from jumping out when the boat hits a wave.


This left photo is looking down from through the edge of the driver's seat with the seat bottom and forward floor section removed. The curved black line is the steering cable. The floor needs to be supported on all sides to avoid excessive bending under my weight.

I fastened batten pieces flush with the bottoms of the stringers to support the sides of the floor. This then sets the height of the floor. Additional pieces were added to the top of the frame gusset that is between the seats to bring it level with the sides and to provide an adequate lip for the two floor panels where they meet in the middle. The forward edge is also supported with a piece of batten stock glued to the rear side of the frame gusset.

At the right side of the photo, the support for the front of the floor can be seen. In the left photo, a close-up of the floor supports can be seen. This is the front corner under the edge of the driver's seat. The brackets are glued and screwed in place. The joints are also filleted to ensure that no water can get in and make for easy cleaning.

Making the floor supports used up the last of my left-over batten stock from building the hull.

Sizing of floor boards

It is nice to try and make the floor boards fit closely so as not to rattle and also provide a finished appearance. You must remember to allow for epoxy coating of the stringers, brackets and floor boards. This means that on the un-coated pieces that you should allow 3/16- 1/4" (4-6 mm) of clearance. Otherwise, once every thing is coated, the floor boards won't fit back into place or will scratch nearby surfaces on the way in.


Try to keep the floor colors light as the floor will get quite hot in the summer sun. As you can see, the front floor boards are lighter than the rear. There is easily a 20 degree difference in surface temperature between them on a hot summer day - very noticeable on bare feet. Replacing the rear floor board is on the "long term improvements list".

Our seats are a burgundy red. We think they are quite attractive, but also get quite hot in the sun as well. You my want to consider a lighter color for that reason. I now understand why most of the commercially made boat seats are white or off-white colored.

Many folks paint the bilge, but I do like the natural wood color, and left it unpainted. Unfortunately, constant submersion and varnish are not very compatible. So, if you intend to keep your boat in the water, the only real choice is to paint. This decision should be made prior to engine installation as once it and other hardware is in place, large areas become quite inaccessible and hard to paint neatly.

Moaning Chair

Overall, fitting out the interior is the part of the project which presents the one of the greatest opportunities for creativity and uniqueness for the boat builder. The myriad choices may seem daunting at first, but by testing, making mock-ups of interior components and just plain sitting in the cockpit areas for a while, the choices do get narrowed down. In a number of Wooden Boat articles there is mention of the boat shop "Moaning Chair" used for contemplation of the next phase of the project or while searching for the solution or fix to a new mistake (yes, we all make them). Why not have it be one of the test seats in the cockpit of your newly flipped hull for a while?

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Last Modified 2/1/03 Copyright ©2003 Mark Bronkalla