Fuel tank placement ???

[Brian.Dixon]

... Don't cuss yourself too much.  The vent / fill proximity issues aren't something that's obvious ...

And yeah ... since it's hard to guarantee 100% zero ignition sources in a pilothouse, under the deck, or in the cuddy ... those fumes simply must be isolated to the fuel tank compartments ... and preferably vented outside the boat or to the cockpit, even if not required.

bd

[Todd j]

The fat lady ain't singing yet boys.  I could support my tanks above the stringers as is by notching them .  Could have some kind of bar across the tanks to sit in stringer notches.  I could put support flanges inside the stringers that sit on the hull similar to what others have done.  Either way I will take Dan's advice and keep it off the floor.  I will not allow the compartments to communicate under decks

[Todd j]

I don’t have any CAD program or skills.  So I drew up my tanks the hard way.  There are some things missing, some I’m just not sure about until I talk to whoever is going to build them.  Almost needed to buy stock in the correction tape manufacturers!

[Dan Boccia]

170 gal of fuel, AWESOME! I'm very jealous.

Raising the floor inside (as well as outside) the cabin is something I had never considered, especially since I have a few tall friends in the 6'4" to 6'5" range that will be on board frequently and I'm 6'2" myself so I was trying to maximize cabin headroom while minimizing the cabin height relative to the rails.....so you went and raised the rails too. Very nice.

Consider that the boat will likely always be something other than sitting perfectly level. So the fuel tanks will also not be level. For that reason, putting the fuel sender in the middle of the tank provides the best "average" fuel depth, whereas putting it at one end or the other of the tank can really misrepresent how much fuel is in the tank overall. So I recommend putting the fuel senders dead center in the tank.

I would recommend having the fuel senders and fuel draw tube assemblies on hand so you can give them to the tank fabricator, they install them, and they pressure test the whole works to ensure that you have a completely leak-free tank to install in the boat. Little additional cost and a lot more certainty.

[Todd j]

The first estimate I got back today was for $2600 for the two tanks.  It was a bit more than I expected.  This fabrication shop has built tons of tanks and I have used them before.  He however can not “ certify “ the tanks.  I have some reservations about using them.  I’m not sure I would be able to pass a coast guard inspection without some paperwork.  I’m still looking into that.  Meanwhile I’m shopping an out of state shop that specializes in tanks and provides inspections/testing reports. 

[Dan Boccia]

That's less than I paid for mine and yours are bigger. However, I just realized I don't see any baffles in your design - another thing I would highly recommend! These type tanks are expensive - I doubt you will save much money going to another vendor, and local is very nice.

Why do they need to be "certified"? Is the CG inspecting your build or do you need CG approval before launching?

[Djeffrey]

I payed $1100 for my 124 gallon tank. Custom built in lake havasu city in Arizona. You must be up north. That is a crazy amount for a tank.

[Todd j]

That's less than I paid for mine and yours are bigger. However, I just realized I don't see any baffles in your design - another thing I would highly recommend! These type tanks are expensive - I doubt you will save much money going to another vendor, and local is very nice.

Why do they need to be "certified"? Is the CG inspecting your build or do you need CG approval before launching?

you are spot on.  I intentionally left the baffles out for clarity.  The drawings get pretty busy.
  I’m not smart enough yet to know about inspections and blessings from the coast guard. Maybe it’s not needed?   I don’t know yet.  Got some digging to do.  If anyone knows feel free to chime in

[Dan Boccia]

Recreational boats are not certified by the Coast Guard. Here is a concise page that explains:

https://newboatbuilders.com/pages/certified.html

[Todd j]

https://www.uscgboating.org/regulations/assets/builders-handbook/VENTILATION.pdf

I read that late last night. I had previously read the above re: fuel tanks.  It’s a lot to cypher.  We will see what the second manufacturer comes back with.  Either way I would be silly not to get a couple bids

[Brian.Dixon]

Recreational boats are not certified by the Coast Guard. Here is a concise page that explains:

https://newboatbuilders.com/pages/certified.html

And ... you don't need a license either (clear up to 100 tons I think) unless you are for-hire and taking paying customers aboard.  I know the Kodiak model seems huge, but it's not THAT huge!

bd

[Brian.Dixon]

https://www.uscgboating.org/regulations/assets/builders-handbook/VENTILATION.pdf

I read that late last night. I had previously read the above re: fuel tanks.  It’s a lot to cypher.  We will see what the second manufacturer comes back with.  Either way I would be silly not to get a couple bids

Thanks.  Note that it pays to double-check the American Boat and Yacht Council (ABYC) guidelines - They are based on real-life safety issues for recreational boaters, and their 'standards' sometimes differ with the USCG.  Because recreational boats are 'uninspected', it's up to you to decide which standards to follow.  If you will use your Great Alaskan as a commercial vessel, e.g. commercial fishing or as a 6-pack captain charter boat, then you will need to meet all USCG rules on your boat (including labeling, life saving equipment etc).

Brian

[Todd j]

Estimate # 2 from out of state shop was 600$ less than the local shop. It’s a 4 1/2 hour drive one way.  Hopefully as I firm up plans so I know exactly what I want prices won’t change much.  I’m having them bid a water tank too while I’m at it.   Will cost much more than a otc model, but should pay me back with a huge savings in space.  I will report back!

[Brian.Dixon]

Estimate # 2 from out of state shop was 600$ less than the local shop. It’s a 4 1/2 hour drive one way.  Hopefully as I firm up plans so I know exactly what I want prices won’t change much.  I’m having them bid a water tank too while I’m at it.   Will cost much more than a otc model, but should pay me back with a huge savings in space.  I will report back!

And if you're happy with the shop(s), give them kudos and post contact info here ....