Thread Tools Search this Thread Display Modes
Old 04-23-2019, 02:01 AM   #1
Senior Member
Country: USA
Join Date: Aug 2017
Posts: 105
Water Collection?

Anybody here collect rain water?

I've been living on the hook on a Marine Trader 44 CPMY for 3 months now, based in Miami. Watermakers are pretty expensive, require engine room space, and maintenance. Once i looked up a chart of how much rain we get in Miami monthly, I've been convinced all I need is a simple catchment system.

My boat has 250gal of tankage, and hardtops over both the sundeck and flybridge, cummulatively about 200 sq ft of roof. An inch of rain yields .6 gal per sq ft. For simplicity, lets just assume I can collect 100gal per inch of rain. Miami avg monthly rainfall (inches): Jan 2, Feb 2, Mar 3, April 3, May 5, June 9, July 7, Aug 9, Sept 10, Oct 6, Nov 3, Dec 2. I expect the "dry" months would yield about just enough for my the wet season it seems i could be downright wasteful.

My tankfill is on my cockpit floor, so its as simple as diverting the water off the roof and into a pipe/hose that threads into the tankfill. Should I go with actual small gutters? Or just rim my hardtops with some sort of lip and cut drain holes at the low points? Curious if anybody has done this, and also what kind of external (pre-tank) filter i should install?

ERTF is offline   Reply With Quote
Old 04-23-2019, 03:00 AM   #2
City: Between Oregon and Alaska
Country: US
Vessel Name: Charlie Harper
Vessel Model: Wheeler Shipyard 83'
Join Date: Jun 2016
Posts: 1,527
Done it but not on a boat. One problem is keeping the roof and gutter system clean. Birds are the worst. Just rats with wings. They carry all kinds of disease and worms. Either they poop or stand on the roof eating their latest prize.

You have to filter and sanitize the water or you'll probably get sick. And what are you going to use for gutters? House gutters? It will make the boat look crummy, greatly reduce the selling price, more than the cost of a small watermaker. You can make a watermaker for under $1000.

Lepke is offline   Reply With Quote
Old 04-23-2019, 05:31 AM   #3
FF's Avatar
Join Date: Oct 2007
Posts: 19,521
Even with a clean collection system the rain water must be filtered before going into your tanks.

All rain drops contain dirt , "condensation nuclei ", that is required for the water to form from water vapor...

Not hard to filter with a std house filter .
FF is offline   Reply With Quote
Old 04-23-2019, 06:25 AM   #4
Senior Member
Country: USA
Join Date: Aug 2017
Posts: 105
Not hard to sterilize with a lil splash of bleach. Plus im not too concerned about maintaining pristine aquifer purity for the water I bathe & defecate in.

And boats are depreciating assets, so im not worried about what the next owner wants -- I'll probably live on it til it sinks anyway.

If i go the gutter route, i was hoping to find a mini version of house gutters (maybe for RV's). But like i said, the other option is to install a raised rim (which wouldnt be noticeable).
ERTF is offline   Reply With Quote
Old 04-23-2019, 07:23 AM   #5
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 7,958
Roof collectors are very common in tropical and high rainfall areas. Large tankage for storage is normal. As mentioned, Filters, UV etc are commonly used for cleanup. Drinking water can be made with a small RO unit.

Price out the options taking into account drought events. Compare to an RO unit and your path should appear.
sunchaser is online now   Reply With Quote
Old 04-23-2019, 09:00 AM   #6
Veteran Member
DCDC's Avatar
City: New Orleans
Country: USA
Vessel Name: Stella
Vessel Model: Seaton 56
Join Date: Sep 2017
Posts: 65
We have used a Sunbrella awning as a rain catcher. Aluminum poles in sleeves at fore & aft ends with a flexible PVC pole in the middle. Bulkhead fitting with hose barb sewn in the middle. Tie high enough to whatever you have overhead. If not raining pull middle upward with rope to arch for shade. When raining release rope, awning will go to a catch rain position. After first flush, hose water to tank.

Works well. We have a sewing machine so homemade, was 10x8, but design is flexible to fit your boat. Wind stable with sufficient tie points. Used while cruising for years with a 100 gal water tank when only other alternative was 5 gallon jugs during dinghy trips ashore.
DCDC is offline   Reply With Quote
Old 04-23-2019, 10:34 AM   #7
Senior Member
City: Pnw
Country: USA
Vessel Name: SARAH TOO
Vessel Model: 40’ beer can
Join Date: Jun 2017
Posts: 178
Hot tub chlorine will help keep it clean also. I’m also considering such ideas. We don’t have much in the way of pesky birds here.
Personally I’d dump the rain water into a simple screen initially, then a more complex filter inline on the tank output side. If you put a pool chorine tablet on the screen as it washes into the tank, it will slowly dissolve and probably keep you right where you need to be with nasty bugs.
Sea Word is offline   Reply With Quote
Old 04-26-2019, 10:04 AM   #8
City: Dallas
Country: Dallas, TX
Join Date: Apr 2019
Posts: 13
Birds are always taunting us

JoeyAboard is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -5. The time now is 04:15 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012