1978 MonArk 16 foot project

[Six Feet Under]

I just picked up a '78 MonArk 16 footer and trailer on Wednesday. Planning on putting a Yamaha/Suzuki 25 horse 4-stroke on it. Intended use will be cave diving (some springs/cave systems can only be accessed by boat due to being surrounded by private or government-owned property, or with extremely long walks from a vehicle), mainly pleasure boating/fishing, and the occasional duck hunting trip. Max weight limit is 1025lbs, the motor I'm looking at is 175lbs, leaves me with 850 pounds of weight capacity to work with.

I'd like to add a floor on top of the ribs, if possible. Also thought about removing the middle bench seat (unless it would cause me to lose structural integrity) to allow for more floor space. Final desire is to paint the boat either dark green or a lighter shade of brown. Anybody know if it would be possible to remove the bench seat in the middle without losing structural integrity? Having the extra space for the tanks required (minimum of two tanks per person, but preferably two sets per diver to allow for multiple dives at a site) and gear assembly would be nice. I'm not planning on climbing back in the boat from the water if we dive from it, but land access to some sites is restricted as I mentioned. All gear could be loaded into the boat or secured to it before climbing in quickly on the bank and then retrieving the gear.

I also plan on adding LED lights to illuminate the inside of the boat at night, a light bar or two on the front (have two 10x2" mounting areas on the bow to the left and right of the cleat), and LED nav lights on the front.

Pics:

 

[g0nef1sshn]

I can see why you would want to remove the middle bench to open it up. But it looks to me that it does provide a structural purpose. I can picture it twisting with out it there over time. What I would do is cut the middle of that bench out and leave two boxes on each side closed up. Add a lid/hatch to each of the for dry storage or batteries. Then once the floor is in use aluminum angle to secure them to the deck you put in. Provided you secure that to the ribs. But I am in no way an engineer on this stuff. Thats just how I picture I would do it.

 

[Johnny]

welcome to the Tin Boats family. A very fun and informative place to hang out.

It would help a lot if you can share where you are from ? maybe update your
profile with the state you hail from so we can get an idea of what water activities you are planning.
also, expand a bit on your past boating experience so that the gallery can lead
you in the right direction with helpful advice.

my boat is very similar to yours and all the seats were removed and replaced with angle
and sheet metal to make a bass boat. It has a side console and remote steering.
Speaking of engineering, you must account for the weight of all those air tanks, gear bags
and your passengers, to be spread out equally to provide the most comfort and safety for everyone aboard.
I see your FL sticker so you must be talking about the FL springs. I have had 3 very close friends
drown in Blue Springs over the years. And they were excellent divers and certified cave divers.
At one time I wanted to be in the Forty Fathom Club, but had second thoughts on that one. (and still do).

Personally, I would suggest to get your dive buddies together and get all your gear together
that you would use for a day out on the water - while your boat is on the trailer, put all that gear
as well as all the people in the boat - and try to figure out how you gonna modify your boat to accomplish your goals.
BEFORE you go cutting stuff up.
There are literally hundreds of threads on this forum about removing bench seats and attaching
flooring to the ribs, how to preserve and protect the plywood, what fasteners, carpet and glue to use.
Just use the Search feature and you will be golden.

jus my Dos Centavos

 

[richg99]

Good advice above. Let me add....don't use treated lumber on an aluminum boat.

richg99

 

[lckstckn2smknbrls]

The ribs look quite substantial, I'd say removing the middle bench is very doable.

 

[Six Feet Under]

As you can tell by the hull ID number, I am from Florida. I plan on spending most of my time on rivers and lakes, some springs, maybe a few coastal creeks here and there. This is my first boat, although I've been boating my whole life on and off (family and friends have always owned some type of boat).

I've done some rough calculations as far as weight estimates, but it would be better if I could weigh each piece of gear and each style of tank separately to get accurate numbers. The remainder of the gear isn't that heavy.

Yes, I am talking about Florida springs I've been diving since May 2013 and I'm working on attaining my cave card now. Honestly, it was kind of a natural progression for me in a way... the guy I dive with regularly has been a cave diver for a number of years and I eventually found a desire to do it as well after swearing it would never happen when I initially got my open water certification. Still haven't made it to saltwater, LOL. Guess the childhood of growing up on the Withlacoochee and Rainbow River and years of swimming in springs had an effect on me. :mrgreen: Obviously it isn't without risk... I've started developing relationships with multiple people in the industry (from instructors to shop owners) over the last year and have already heard of multiple fatalities of friends of theirs in the last 9-12 months alone. Good thing I take it slooooow when it comes to training... definitely not rushing anything. As my instructor says... the caves aren't going anywhere!

As far as getting everything in the boat, I plan on doing so after I adjust the rollers and bunks here and there to help support the weight of the boat and cargo a little better... it definitely needs some adjustment. I'll probably do that at the same time I re-wire the trailer. It works, except for the driver's side tail light being intermittent. I want to make everything LED and add two or three amber clearance markers on each side of the trailer, as well as a set of lighted guide-ons to assist in backing the trailer and loading the boat. Looks like everything I need to do so should be about $120 on Amazon.

Also believe I'll be getting a Suzuki 25 horse, manual tilt/trim with electric start and tiller steer. Weighs about 143 pounds if the website is correct.