Black Water tank location on R27OB

[venajeff]

Does anyone know if there is a way to access the black water tank? There is a 3" access hole inside the step bilge area but that is the fresh water tank on my boat. I am trying to find a spot I can stick a sensor on the side of it.

 

[Submariner]

The only access really available is through that 3" access hole via the step in the v-berth.
The only other access to the tank is from inside the cave.

This is what it looks like (pic taken of the boat being built)

2974E430-B880-4B54-8139-73C61B3E2DE7.jpeg | Boat Maintenance (Project Name)

www.letsgochannelsurfing.com

This is the owners view, from within the cave, after the boat's built.

008A34FD-A65A-4B2F-84B7-08933A14F932.jpeg | Boat Maintenance (Project Name)

Access to the top of the freshwater and holding tank.

www.letsgochannelsurfing.com

Our boat's a model '21, we don't even have that 3" access hole. We just count days. 1 gallon per adult per day. So 3 adults onboard, it's a 30 gallon tank, we get 10 days. By day 7-8 we're looking for the next pump out. It's worked well for us.

 

[venajeff]

That image during construction helps a lot. Maybe my forward tank is the black water. I tried my best to look up in through that access port and it looked empty even though I had filled it, but it is very hard to get a good view of it.

 

[Submariner]

That image during construction helps a lot. Maybe my forward tank is the black water. I tried my best to look up in through that access port and it looked empty even though I had filled it, but it is very hard to get a good view of it.

Yeah, the only way that 3" access port is useful is if you see the fluid level, the tank is 3/4 or 7/8th full. If the tank were 100% full, then you probably couldn't tell looking in the 3" access port.

Like I said, our R27-OB, being 2021 model, doesn't even have that access port. They started putting that access port in for the 2022 models. The only way we know that our tank is full is when the toilet backs up and won't flush. It's not really been a problem for us using the 1gallon per adult per day calculation. We also do other things like, after a trip, we usually will pump out. We don't want the tank to sit partially full, during hot weather, during boating season.

In Canada or SE Alaska it's more common to macerate overboard as pump outs are either rare or non existent. Life gets easier in that scenario. Whenever I find myself 3nm or further offshore, macerate overboard regardless of how full the tank is. Keep it mostly empty. It's only in Puget Sound/San Juan Islands we have to manage the level based on our usage.

 

[venajeff]

I think you are correct on what happened. I confirmed that it is the black water tank. I am going to try to install an induction level sensor on the side of the tank through that hole. Then install a tiny LED above the toilet flush switch.