Notes from our bow thruster install as promised.

[mark....@gmail.com]

Our slip is bow in, starboard side tie up with a back out in a narrow fairway. The entry into our marina is tight and confined. Needless to say docking was a problem. Even though the boat is only 39 feet we decided to go ahead and have a BT installed.

I researched the market and shortlisted my preferred suppliers (Sidepower, Vetus, Max-Power, Lewmar) and looked for local installers (see earlier post for the alternative vendor I vetted who was going to install a Lewmar unit) but in the end I went with my local marina (big chain) because they were on site to warranty the work and would pull the boat etc at their expense if needed and we installed a side-power model - I THINK the SE80- certainly it's a twin prop variant

We had the boat inside the shed for the work during the wintertime - better control on the glasswork, this necessitated dropping the mast but the inside storage fee versus external storage was included in the project cost and I was also able to take advantage of the boat being inside to get some other work done too.

Measurements done with the boat in the water proved misleading. The 381 has a shallow foot and the BT tunnel needed to go farther back than anticipated - this is where my water tank was. It also necessitated a one size step up in thruster size because the tunnel was farther back than anticipated. The top of the motor clears the bunk by less than an inch so I added additional oak support beams (Home Depot)for the mattress boards so that people sleeping would not cause contact with the top of the motor

The tunnel originally ordered was 1" too shore (48" v 49") because they had to move it backwards, the yard did the right thing and ordered the 54" tunnel rather than trying to fudge the gap with epoxy. I of course paid the $ difference (minor). The glass work was excellent, they also covered everything in plastic sheeting and did a neat job inside and out.

I did all the wiring (planning, ordering, install) myself. I purchased cable from an online provider - made up to size with connections. I installed a Lifeline Group 27 AGM starting battery under the v berth and a hi capacity shut off switch in the side of the cabinetry. All connections were rubber booted. This is effectively an independent closed circuit (0 or 00 Gauge wire) - battery - switch - motor - battery. thus my heavy gauge wiring runs are relatively short (good job because that cable is not cheap). I did inter connect the ground circuits at the windlass ground. I charge the battery using a Balmar duo charge from the house (via 10 or 12 gauge wire I think - it has to act as a spring over the 35ft distance) which was my other upgrade at the same time. In fact all my charging sources now charge the house bank and that bank now charges the BT battery and starting battery via 2 separate duo charges.

The control switch is at the helm. I went with the touch pad not the joystick so it did not get snagged by sleeves/ pfd's etc as it might it the joystick itself protruded. I have to reach over the wheel to reach it bu that's OK. I ran the control cable down the starboard side of the boat, behind the seating, nav etc, through the lazarette and into the existing ribbed conduit that runs around the quadrant and into the binnacle - here I found I was 2 feet short so after consulting with the electrician in the yard I spliced the cable - it is straight electrical connections not speciality connections like radar - I cut the cable, added an 8 core splice with shrink wrapped connections inside radio shack project boxes - one in the binnacle, one in the lazarette and retained the standard plugs on the ends - if I had to do this again I would make the splices in the v berth at the BT end, not in the lazarette/binnacle.

The yard closed in the water tank - if you think about the bow section under the v berth as being divided into three sections of a triangle, each getting wider as they come back - the original tank (integral to the hull liner) was in sections 2 and 3. The BT is now in section 2 so the yard fiberglassed over a sheet of marine ply and created a bulkhead to close in the tank again - just all of section 3. You have to use a special type of resin for this as it is a drinking water tank (not that we drink from it). They did a great job and the tank is solid and watertight - it did take almost half a day during commissioning though to vac/rinse/pump/repeat the tank to get it clean. I lost maybe 40 gallons of capacity.

I would get a written quote detailing what is included and what is not./ I would outline in that agreement how a change of scope will be addressed and whether there s a cap on total cost (vendor carrying the risk basically). Make sure you know whether haul/splash, storage, stepping mast etc are included. You could also source major materials yourself so as to avoid mark-up, or negotiate that too - we saw a substantial amount of consumables in the final bill, chip brushes, tyvek suits, grinding pads, epoxy, bottom paint, plastic sheeting, acetone, tape etc - some of this was definitely not what I would call street price and I know the yard has to cover their overhead in ordering and supplying and I am all for a fair days pay (or profit) for a fair days work but either check this beforehand or be prepared for a surprise. environmental disposal fees etc also added up too.

BTW - it's not just for docking - it can also be useful when grabbing a mooring ball if you mess up the approach or get caught by a gust PROVIDED you are careful not to suck the pennant or pick up line into the prop

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