Cleaning up the console wiring

New Wahoo!s came with lots of different makes of motors: Mariners, Mercs, Hondas, Suzukis, Evinrudes, Johnsons…it doesn’t appear that Wahoo! had exclusive deals with specific manufacturers. Maybe it was the dealers who made the pairing of boat and motor. Or maybe in some instances the buyer made the choice. I don’t know.

Regardless, the motor that came on your Wahoo!, whether the original or one added by a  subsequent owner, determines the wiring harness on your boat. And the wiring harness determines in part how the switches and gauges in your console are hooked up.

My 87 Striper 16.2 came with a 1981 50 horse Evinrude. This was obviously not the original motor since it predated the hull by six years.  I wanted to replace it with something more recent but didn’t feel like replacing the wiring harness for this reason: Wahoo!s are a pain in the butt to change harnesses on. Maybe this can be said of most boats but it’s especially true of Wahoo!s because the sprayed-in foam below deck makes for really tight quarters when it comes to running wires and cables. (To illustrate the point, last summer I added a new Garmin Humminbird fishfinder to Seatoad. The plug for the transducer, which needed to pass under the deck and up through the wiring port in the console floor, was about the size and shape of a champagne bottle cork. I literally spent two weeks trying every way imaginable to fish that sucker through a chokepoint of cables running under the deck through a VERY narrow crevice in the foam. Wasn’t happening. I finally gave up and ran the transducer wire over the top of the deck, covering it with a protective hood of 3/4 inch PVC pipe I’d  cut length-wise.)

So when I bought a “new” motor I went with a Johnson, one that could use the same OMC wiring harness already installed in my Wahoo!

Inside the console itself the wiring was spaghetti. Wires running every which way, some hooked up to nothing at all. The only working gauge on the dashboard was the tach and even on that the backlight didn’t work. It took awhile but I finally got most of it straightened out. First thing I did was install a fuse hub like this for all fused accessories. I also installed a bus bar for all the various ground wires that were spliced together all over the place like a tangle of mating eels. Where wires were just barely long enough to reach the post they were supposed to reach I lengthened them to relieve the strain on them. And every join I sheathed with heat shrink rap or electrical tape.

Really useful in getting things back together and ensuring everything was connected properly  was this OMC wiring diagram from Continuous Wave. Continuous Wave has lots of other very useful reference material as well.

In the end, two of the existing non-working gauges I decided not to bother with. The tilt/trim gauge really doesn’t tell you anything you can’t see with your own eye. And the speedometer is superfluous these days–I can get my speed from my GPS.  I left both gauges in place for now, they’re just not hooked up. Eventually I’d like to replace the tilt/trim gauge with a dash-mounted fuel gauge. The other I don’t know yet.

There are some still-unsolved mysteries in the wiring, such as the the engine alarm that won’t turn off and and a superfluous accessories ground ground wire. But I’ll save those for another post.

Wahoo! bilges: an explanation

As a companion piece to the post on the Wahoo!s above-deck drain system, here’s one on the Wahoo!’s below-deck plumbing. Like the self-bailing deck, the Wahoo! hull interior is one of the most confusing features of these boats. As with the post on the deck drain system, I’ll update this article if and when new info becomes available. Note also that this post deals specifically with smaller Wahoo!s–the tri-hull models. For all I know the larger Wahoo!s (say, those over 21 feet) and/or the V hulls had a very different design. So your mileage may  vary.

The Wahoo! hull: What’s in there?

Basic to understanding the design of a Wahoo! is knowing what’s going on insider the hull. Some key points:

Wahoo! hulls contain foam. This helps with buoyancy of course. Boston Whaler hulls are foam “filled.” The “filled” part means every bit of the hull interior is filled with sprayed-in foam. This not only maximizes buoyancy, it also in theory keeps water out of the hull because there’s no literally place for it to collect. But there are a few potential drawbacks to this design. For one, because there is the assumption of no water ever entering the hull, Whaler hulls do not have a drain plug. That means if somehow water DOES manage to get in there, there’s no easy way to get it out. A second concern is that over time the hull foam may begin to absorb water, not unlike a sponge. The water could come from the outside or it  could come from condensation inside the hull. Either way, as the foam absorbs water it takes on weight. That causes handling problems. And over time the moisture can cause the foam to break down.

Distinct from Whalers, Wahoo! hulls are foam “lined.” The “lined” part means that the top, sides, and bottom of the hull interior are coated with blown-in foam but there is an air cavity in between. Also the Wahoo! hull includes a drain hole in the stern. The advantage of this design is that the cavity allows the interior foam and stringers to “breathe”; that is, the ability to dry. And any water that does get into the hull can be drained. The downside, compared to the Whaler design, is that with less foam comes less buoyancy, and the air cavity allows water a place to collect.

Cutaway showing Wahoo! foam liner and air cavity.

The original Wahoo!s from the mid 80s design did not include a bilge pump. Since that time 25 years’ worth of Wahoo! owners have wondered why, because water certainly finds its way into Wahoo! bilges, as it does with any other boat. It’s not immediately clear what the the absence of a pump meant from the manufacturer’s perspective. Maybe it meant the company  had a misplaced faith that water wouldn’t get into the bilge. Or maybe it meant they assumed that most Wahoo!s would be used as trailer boats whose drain plugs would be opened after every use. Or maybe it was simply an attempt by the company to cut costs and leave it to customers to add their own bilge pumps. Whatever was behind the initial decision to omit a pump, it was not adequate. Within a several years Wahoo! brochures began mentioning an “optional” bilge pump.

How water gets into the hull

So does your Wahoo! need a pump in the bilge? First, let’s talk about the ways that water can get into the bilge. Leaving aside leaks in the hull exterior (but all the more reason for a bilge pump), you have:

  • Condensation (aka “hull sweat): If you store your boat in the water, condensation will form inside the hull. The amount will vary based on temperatures but can easily result in a gallon a week of water in the bilge.
  • Cracks in the deck drain system: The Wahoo! deck drain system (discussed in this post) consists of a series of deck flanges and below deck PVC tubes. It’s quite possible for these to develop cracks that allow water into the hull.
  • Power and steering cable deck port: On many Wahoo!s the power cables from the battery and the steering cables from the engine pass into the hull and then up into the console through a hole in the the deck. This deck hole can allow quite a bit of water in.
  • Access ports: Access ports, either original or after market, are notoriously leaky.
  • Other screw holes or cracks: Lastly, any screw hole in the hull, especially the deck, if not properly caulked, can allow water to leak in. After 25 years or so, odds are good at least some of the screws securing your console to the deck are not sufficiently caulked any more.

These things together or alone can allow quite a bit of water into you hull. Water is especially good at finding its way in when its got some force behind it, such as wind-driven rain or when you’re hosing the deck. Given the relatively small size and weight capacity of Wahoo!s, and that a gallon of water weighs seven pounds, it doesn’t take much to affect performance.

Adding a pump in the bilge

So to the question of whether your Wahoo! needs a pump in the bilge, I say the answer is, yes, absolutely. Even if you keep your boat on a trailer, the added safety and security that a bilge pump gives you make it well worth it. The installation is easy and inexpensive. I would not waste time considering a manual pump–put in an electric one and be done with it.

Locate the pump in the spot shown in the diagram above, at the rear of the bilge along the keel. This is the lowest section of the hull and where all water will run to. Most Wahoo! tri-hulls come with a five inch access port in the center of the stern through which you can install the pump. If  yours does not include an access port you’ll need to add one.

Here are a few notes on the pump I installed in case it’s helpful to anyone. There are certainly other ways to do it.

  • I chose just about the smallest pump possible, a Rule 360. It fit easily through my existing access port and its capacity in more than adequate for my 16.2 Striper.
  • I chose not to install an automatic float switch. But I can get away with that because the marina where I keep my boat is ten minutes from my house. So I can run over there any time to turn on the pump. If I had to leave the boat unattended for days or weeks at a time I would add a float switch or one of those chip driven pumps that cycle on and off checking for water.
  • For mounting the pump, I did not want to screw into the hull. One alternate mounting method I read called for gluing in a piece of marine grade plywood and mounting the pump on that. But I decided that was overkill. Plus it would have raised the pump up 3/8 to 1/2 an inch from the bottom, allowing that level of water to sit unpumped in the bilge. The simpler solution was to apply some 3M 5200 directly to the bottom of the pump’s basket and glue the basket right to the bilge floor. In 10 minutes I had a well-fastened mount that isn’t going anywhere.
  • The hose I ran it straight up and out of a hole I drilled in the access port cover. Like the pump I installed in the deck sump basin, the bilge pump drains into the splashwell.
Rule 360 bilge pump. Hose from bilge pump exists through hole in access port cover and drains into splashwell..

A one pump system?

Just as I was finishing this post I wondered whether anyone had ever configured his Wahoo! so that a single pump handled both the above and below deck drainage. You could achieve this pretty simply by installing a pump in the bilge and then drilling about a  one inch hole in the bottom of the deck sump basin. That would dump all water that enteredd the boat into the bilge. It seems like a bad idea for a few different reasons, but man if anyone has ever tried it I’d love to hear how it went.

More reading

Here’s a little more reading on the subject:

(Note: in this message thread Monstawhala states that the top hole in the deck sump basin drains into the bilge, and that both stern compartments also drain directly into the bilge. That is not correct. The stern compartments drain into the sump basin via the aforementioned top hole in the sump basin.)

Wahoo! self-bailing decks: an explanation

There are two things I’d planned to write about this winter: the Wahoo!’s above deck drain system and the Wahoo!’s below deck drain system. Both are among the quirkiest aspects of these boats and among most commented on/asked about. They sure had me stumped when I first bought my Wahoo! It’s the third week in February all of a sudden and Spring is just around the corner. So time to get writing before the boating and fishing season take over.

This post will be about the Wahoo!’s above-deck drain system. Specifically it will be about the self-bailing deck drain system employed by most smaller Wahoo!s, whereby water from the deck is designed to exit out of a scupper in the stern. I may not get all the facts complete or correct the first time. So if you are are a Wahoo! owner past or present and have corrections or additional info, please add a comment or send an email. I’ll continue to update this article as necessary.

The self-bailing design concept

Smaller Wahoo!s have a deck draining system that is designed to be self-bailing. The idea is that, when underway, any water that accumulates on the deck, be it from rain, spray, waves over the gunnels, or whatever, is designed to run to the rear of the boat and collect in a small sump basin located just inside the stern. A scupper connects the basin to the outside of the boat. Gravity from the boat’s forward motion forces water from the sump basin through the scupper and out of the boat. (Note that it is only the Wahoo!’s deck only that is designed to be self-bailing, not the hull interior (that is, the bilge).) Continue Reading…

Mass boating registration, taxes, and other fees

I have a tendency to forget what bills are due when. But those jamokes in the government never do. So for my own reference I put together this check list of all the annual government fees related to my boating. I included my Seatow membership dues in the list as it’s another fee I might forget otherwise.


Fee Due Description 2012 Cost
Boat registration August 9 of every even numbered year In Massachusetts boat registration is good for two years from date of issue. The state is supposed to send a reminder one month before the registration expires. Can be renewed online. $60 (for 2 years)
Boat excise tax By August 1 (according to the assessors web site) In Massachusetts, excise tax on boats is paid to your town of residence or where the boat is principally situated. The tax applies to boat 16 feet and up. The current rate is $10 per $1000 of assessed value.  $10
Trailer registration Before you hit the road In Massachusetts your trailer must be registered annually. The registration is good for the calendar year. Can be renewed online. $40
Trailer excise tax In my town, Feb-Mar (according to the assessors web site) In Massachusetts your town of residence is responsible for charging and collecting excise tax on trailers. The current rate is $25 per $1000 of assessed value.  $15
SeaTow membership September 28 Good for one year (365 days). $169
Freshwater fishing license Whenever Good for calendar year. Can be purchased online. $27.50
Saltwater fishing license Whenever Good for calendar year. Can be purchased online. $10


Paperwork Storage:

As proof the afore-mentioned levies have been paid, I keep the following documents in these locations (with copies of each at home):

  • Boat Registration: On boat. (Required by law.)
  • Trailer Registration: In towing vehicle. (Required by law.)
  • SeaTow Card: In wallet. Also keep copy on boat.
  • Freshwater Fishing License: In wallet
  • Saltwater Fishing License: In wallet. Also keep copy on boat.