Waste & Water Tanks

All marine holding tanks, waste tanks, water tanks and fresh water tanks are made to order.

Our wide variety of marine tank shapes and sizes can be sorted through using our tank finder below. All fresh water tanks and holding tanks used for marine sanitation are roto-molded polyethylene without seams making for a strong tank that will not split allowing for a more reliable container for your fresh water or sanitation needs. All fill and out flow fittings will be installed to your specifications making sure that it will match up to your requirements.

How to Search for a Tank

Start by choosing the shape of the holding tank or water tank based on the location it needs to fit into. Next insert the dimensions. You may also insert a specified amount of gallons. Our tank finder will sort our large inventory of tanks and come up with a number of suggestions.

Utilize the search boxes below to start your search and if the tank size you are looking for doesn’t come up give us a call at +1 (401) 683-4434 or e-mail us at info@oceanlinkinc.com and we can talk with you about a custom built tank.

Our Tank Selection Guide

Search By Gallons
Search By Tank Number
Tank Number must be preceded with
"OLT" or "WT" for Waste & Water Tanks
or "FOLT" or "FDOLT" for Fuel Tanks*
*FDOLT tanks are Diesel Tanks

Rectangular Tanks

Rectangular Tanks are, as you may expect, rectangles. We have hundreds of Rectangular tanks, so we are providing you a great way to search for the size tank you are looking for.

Largest Measurement Middle Measurement Smallest Measurement (in)

Bow Tanks

Bow tanks are designed to fit in the bow area of your yacht. Many boats have unused space under a V-berth where a bow tank makes the best use of the available space.

Largest Measurement Middle Measurement Smallest Measurement (in)

Keel Tanks

Keel tanks are shaped to fit in the bilge or keel area on centerline.

Largest Measurement Middle Measurement Smallest Measurement (in)

Side Tanks

Largest Measurement Middle Measurement Smallest Measurement (in)

Side tanks are shaped to fit along the side of the yacht. Many people find a spot under a settee which is perfect for a side tank. When selecting a side tank, be sure to check for “handedness”, some fit better port or starboard

Other Tanks

Other tanks are oddball shapes with funny notches and cutouts. While hard to categorize, you may find one that’s perfect.

Tank Measuring Guide for Waste & Water Tanks


Bow Tanks

To measure for a bow tank, attach a string fore and aft in the compartment at the height that you think the top of the tank should be. Next, at three inch intervals along the string measure the depth of the compartment. Using the same three-inch intervals measure the width of the compartment. Now you will have some data to use when looking at the list of tanks. You can use the same method in reverse if you have the dimensions of a tank. Set the string at the tank height and make sure all of the boat’s dimensions are larger than the tank’s. If the space is too close to call, then make a cardboard mock up of the tank and see if it will fit. Finally check to see that the tank will fit down the hatch and into the tank bed!

Pick up your phone and order the tank right away, call: +1 (401) 683-4434

Side Tanks

Start at the deep side of the space and determine the height. Then measure the width of the space at the forward end and try to make a reference line on the bulkhead. Now measure the depth of the space every three inches along the reference line. Take the same measurements at the aft end of the space. Now with your data check to see which tanks will fit. When you select a tank double-check the tank measurements in the boat. Check to see that your tank will fit through companionway to its final resting-place.

Now run, don’t walk to a phone and order the tank, call: +1 (401) 683-4434

Rectangular Tanks

Measure the longest dimension first then the other two lengths. All the rectangular tanks are listed with the long side first. Often it is easier to partition an odd shaped space and put in a rectangular tank or two, than trying to fit and odd shaped tank into an odder shaped space. Especially when you need to put in a platform for the tank to sit on.

Once you have selected the tank call me A.S.A.P. with your tank order. +1 (401) 683-4434

Get a tape measure, a cell phone, a pencil, a pad, some string, some scotch tape, and my phone number. Go down to the boat and we’ll chat. +1 (401) 683-4434.

Tank Fittings

Discharge Fittings (waste)

We use dip tubes for discharge, they can be located on the top side or the top of a vertical side. Dip tubes are 1.5″ female pipe thread and will accept straight or 90-degree pipe to hose adapters. Dip tubes extend down to the bottom of the tank. You will need 4.5″ of clearance from the sidewall of the tank for our standard fittings and 2.75″ for our low profile fittings.

Inlet and Vent fittings

Inlet and vent fittings can be located on the top or the top of a vertical side of the tank. The inlet fitting is 1.5″ female pipe thread and the vent can be .5″ or .75″ female pipe thread. The inlet fitting requires 4.5″ of clearance from the sidewall of the tank for a 90-degree fitting. Vent fittings require 2″ of clearance for .5″ 90 degree fittings and 2.25″ of clearance for .75″ fittings off the sidewall of the tank.

Suction Fittings (water tanks)

Suction fittings can be at the bottom of the tank or the bottom of a sidewall of the tank. Suction fittings can be .5″, .75″, or 1″.

Waste and Water Tank Ordering Instructions

Before you order your waste/water tank make sure you have completed the following items:

  • Select the tank that you would like by choosing an OLT #
  • Complete a diagram on how you would like to have the tank set up depicting the exact locations of FPT fittings and dip tubes. You can use the schematic for the tank you are ordering from the web page and add the fitting locations.
  • Select the proper fittings or dip tubes from our web store, based on what is on your drawing, and added them to your shopping cart.
  • Check the shopping cart and made sure that all items are accounted for and billing and shipping information is correct.
  • Fax or email us a copy of your diagram so that we can build the tank to your specifications, again this is very important because all sales are final there are no returns on tanks.


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If You Are Ordering A Waste Water Tank