Islander bow thruster

[Halfhitch]

Now there's a topic we can all get a grip on....pissing over the side. Do wide gunnels present a problem? Are cockpit drains fair game? Is it poor form to help hold onto a guy to keep him onboard? Ha ha ha. Russ you made my day.

 

[Fishtales]

Don't take differing opinions the wrong way guys. To each their own. Some things to consider.
Checking GW, they don't offer the thruster as an option until the 30' hull boats. There is demand for it, I'm sure they'd offer it. If you want a thruster, I say get one. That being said, if you ask 20 people on the docks if you should have a thruster a <30' boat, I think you'd be lucky to get one person to say yes. Boating around the dock comes down to confidence and experience which comes from practice. if you do it enough and learn your boat, the current and wind implications you will be able to handle it. Once your in the 30+ foot range the need rises with length if you ask me.

 

[RussGW270]

Oh I was not offended by you at all I have a father in law that was like “You built a cabin at your ranch? That is not camping” and people think that. I love they enjoy camping. I also love sitting on my porch watching the rain and thinking, “I sure bet they are cold” .....as they sit in their tent. Lol

But, seriously...a bow thruster is personal and I am also sure if you asked those people if they would take one for free, they’d do it.

It comes down mostly to that people are willing to pay for, more than a stalwart belief in the lack of need.

Either way, to each their own and I still like ya ...lol

 

[Hookup1]

Bow thrusters are a popular option on the newer boats. Grady White's 271 has it designed into the mold.


They are using a Side-Power SE60 (132 pounds of thrust 7" tunnel). The 7" tunnel is difficult to place in a 268 (8' 6" beam vs. 9' 6" beam). Options are Side-Power SE40 (88 pounds of thrust 5" tunnel) or Vetus BOW4512D (99 pounds of thrust 5" tube). I ordered the Vetus. Defender had a big sale over the weekend. Around $2k for the parts. Add a battery charger, group 27 AGM battery and charging shunt for 2nd engine, 20 hours of my labor at $1/hour and we're under $2.5k. Side-Power would have been $500 less.

Need to fine tune placement when the parts arrive. Would like to move it 8" or so forward but I'm tight on tunnel length. Should be OK though with flare on front of tunnel.


Decided on the final placement. When you mark out the parameters on the hull your left with little choice. 4" in front of interior bulkhead, 10" tunnel on bottom, not too close to bottom, 1 1/2 times tunnel diameter below water line and as far forward as possible. With brow/spoiler on leading edge of tunnel we pickup another 1.5" and the prop can be centered. Raised tunnel and cut strake but will probably re-build for cosmetic reasons - angled tunnel cuts add surface area to tunnel and won't interfere with flow.

Inside this puts the tunnel slightly above the old floor in the compartment. The floor was glassed in to backup the strakes so we'll do the same.

 

[Mr.crab]

Just fix my bow thruster the other day , put 50 hrs on my Marlin without much better when needed.

 

[Hookup1]

Just wanted to update this thread on my progress should anyone want to take this project on for their own boat. Floor was cut out in forward compartment. Tunnel placement has 3" clearance behind it and access under tunnel for fiberglass work. The hull at the base on the tunnel is 10" wide. Tunnel tube extends out in the front and bottom part of the tunnel and a spoiler formed to deflect water away from back of tunnel. Finished tunnel is 12" wide at base (Vetus spec).

As I said above in this post Side-Power gives you more placement options with a narrower tunnel but less thrust. Also smaller HP motor gives you more runtime on battery. I went with a group 34 AGM (24 pounds lighter than a group 31, MCA is close but capacity is half).



A little hard to see but tunnel edges are 1/2" radius and extend out on forward / bottom and taper back to flush at top and rear



Final installation of battery, switch, fuse, charger and motor. Glassed in supports for floor and screwed it down. Hopefully it will never have to come up.



I need to mount control at helm and run a charging shunt from other engine for on-the-water charging. Splash next month. Came in around $3,000 doing it myself. Then estimate I got from a Florida company that does this everyday was $8,000. But I'll tell you they work hard for that $5,000. Cramped space, standing on your head,, bruised ribs, dusty dirty work.

 

[ocnslr]

Congrats on the installation. Looks great.

I'm sure you will find it very useful.

 

[RussGW270]

Outstanding job. While this may be "on my list"... lol.. my list is long and far-reaching.. heh.. costs etc. Will love hearing how much it helps you. My concerns is the strength of the structure/hull after the hole is there. Curious how well it holds up...but, yea, awesome job.

So you say you did it for like 3k yourself?

I would say it is well worth a 5k savings...just need a nimble helper

R

 

[Hookup1]

Its actually stronger after the install. The fiberglass tunnel is like a hollow cross beam. The original floor added stiffness to the strakes. The supporting plywood for the new floor was glassed to the strakes and the floor screwed down.

And yes it was about $3,000 cost (a $5,000 saving over turnkey). You could subcontract parts out (fiberglass) and still save a bundle.

 

[Legend]

Tight spots, wind and strong tidal currents can make docking very challenging or impossible. Some day I will be installing a thruster. Looking forward to see the finished product

 

[Hookup1]

Your looking at "finished" product short of some electrical work. I'll let everyone know how its works when its in the water. This is probably the right combo for a Sailfish. May be a little more than I need for an Islander. Thanks to everyone for the comments.

 

[Hookup1]

Went one step further by relocating windlass power from the aft battery to the new one in the forward compartment.
Installed charging shunt on port engine and re-used old #10 windlass wires to bring charging power forward.
Added reversing relay (old Horizon windlass was direct) and upgraded windlass wires to be ready for new Lewmar 700 at some point.

 

[Hookup1]

Finally got the boat in the water to test the bow thruster. Works great!

I used a Group 34M Duracell Marine AGM to reduce the weight in the bow. Almost 25 lbs lighter than a Group 31 with similar MCA rating but less capacity. Plenty of power to get the boat turned around in a tight canal and to the dock.

Group 34 43.10 lbs. 955 MCA 55 AH
Group 24 52.40 lbs. 800 MCA 78 AH
Group 27 61.55 lbs. 900 MCA 92 AH
Group 31 67.35 lbs. 1,000 MCA 105 AH

 

[usmm1234]

It’s all personal in what you want or need. If you are not an experienced Captain. A thruster can help you and your family enjoy the whole experience more. I own a 330 Express and do not have one. My company represented Max Power Thrusters for years. We sold a lot of them. We had the Searay contract for awhile. I choose not to have one due to all the battery requirements needed up front. The charging releases gas in the cabin. The weight is substantial too. Lastly. It is one more thing to keep working. Chargers, batteries, switches, relays, etc. I’m also 63 and have been an experienced Capt since I was 20. The motors On the 330 are very far apart, so the handling in the marina is outstanding. I put the boat in the travel lift slings this morning in a 15 knot quartering wind with ease.
If we end up in a large sailboat or single screw trawler later on in life. I will have one.

 

[Hookup1]

It not inexperience. Read the post from the beginning. This narrow beam Grady with twins and a lot of house surface area is difficult to handle. I can get the boat in the slip but my family members are afraid to use the boat. Bow thruster is an important safety and usability upgrade for me.

As far as the installation, its all about the right design. The instillation replaced a 13 gallon water heater that I didn't need. Batter size carefully chosen with weigh in mind. AGM batteries do not outgas and are suitable for non-vented installations. If the work is done right the first time it shouldn't be a maintenance problem down the road.

Do you have AC or a generator? These are bigger PITA maintenance items that are unnecessary conveniences.

 

[usmm1234]

It not inexperience. Read the post from the beginning. This narrow beam Grady with twins and a lot of house surface area is difficult to handle. I can get the boat in the slip but my family members are afraid to use the boat. Bow thruster is an important safety and usability upgrade for me.

As far as the installation, its all about the right design. The instillation replaced a 13 gallon water heater that I didn't need. Batter size carefully chosen with weigh in mind. AGM batteries do not outgas and are suitable for non-vented installations. If the work is done right the first time it shouldn't be a maintenance problem down the road.

Do you have AC or a generator? These are bigger PITA maintenance items that are unnecessary conveniences.

View attachment 10783

I agree completely with you. If a thruster aids you in any way, and you have the room and $ for one. It’s a sound investment. I just like to keep things as simple as possible.
You mentioned AC and Gen set. AC is a necessity and is trouble free and used constantly. My 3 year old Kohler Gen set should become part of a reef somewhere.
Your installation looks great And battery technology was not there when I was selling thrusters. As I said. It all depends on the boat and the skipper. My friend has a 36 ft center console that would be impossible to get back on the lift without the thruster, and he’s very experienced. My 330 with huge 4 blade props and wide separation of the motors. It’s is like driving a bulldozer. I can’t imagine needing a thruster. (saying that. I’ll probably crash into 5 boats in the Marina on the next windy day,) Cheers!

 

[jerseytiger10]

I’ve had them one 2 boats. Nice thing to have.

 

[RussGW270]

I’d put one on but my boat is afraid of water...lol. Seriously, on my list but not in the top 5.

 

[Steelhead]

I'm not a glass guy either. But I'm an awesome amateur sheetrock guy. Not really the same though. It a big leap of faith to cut two 5" holes in you boat! I have done some glass repairs on a friends salvage boat that folded a rudder over. It's been good for 10+ years now. This bow thruster is a pretty straightforward project.

Thank you for sharing this installation , looks awesome ! I will be doing the same mod to my islander this fall , how far forward is your tube from the bulkhead ? The height was not an issue for the forward compartment cover to go on ? Thank you again for sharing

 

[Hookup1]

Thank you for sharing this installation , looks awesome ! I will be doing the same mod to my islander this fall , how far forward is your tube from the bulkhead ? The height was not an issue for the forward compartment cover to go on ? Thank you again for sharing

I installed a Vetus BOW45D from Defender #305883. When you plot out all the parameters it winds up being a very small area it will go into. About 3" forward of the bulkhead. Headroom is no problem. I replacer the "floor" with a screw down one just in case you need to get down there. I really like my Duracell 34M AMG right next to it from Sam's club. Thruster positioning was a little higher into the strake slightly than the plan. Couldn't be happier with the results.



How about this....from the top center of the tube to the bow is 27".


I would recommend the Vetus. It's a class above the SidePower. No drama - it just works!