Boat Speed problems with my Hunter 386

[Dave22q]

Originally Posted by ryall

Exciting! Can't wait to test this!

Quick related question. If I manage to get it taken out today, I just spray it with a pressure wash until the antifouling is off, wait for it to dry, and repaint with a new coat of antifouling, right?

Sorry Rydal. You can no more remove paint from a boat with pressure washing than from a house. However, the good news is that scraping and sanding before applying a new coat generally works. Before signing any work orders remember that no boat ever was slow because the paint was old. First clean it in the water and then look for other reasons for poor speed. A good point is to check your speed transducer. A little crud can result in false speed readings. You can easily check your boat speed by timing a measured course. Do not start throwing money at a problem until you are sure it is real.

[ryall]

Originally Posted by UNCIVILIZED

Question? Did you not take the boat for a test sail as part of the pre-purchase process? Ditto on hauling her out as part of the survey? And those are just a couple of the standard checks.
So if they were skipped, you'd be wise to do a good bit of studying on the boat buying process. Probably before having her hauled, so that you're more knowledgeable of what bo both expect, & look at when you do have her hauled.

That, & vett a few surveyors, & then have the top one present when you have the boat hauled. So that he can inspect things in order to make recommendations to you in terms of what maintenance below the waterline she may need... aside from a good cleaning, & probably new antifouling.

There's plenty of info on both pre-purchase checks, & checklists here on the forums, as well as online. And the same is true about surveys, & surveyors. With boatpoker's site on; boats, surveys, & surveyors being a good one. Marine Surveyor, Port Credit Marine Surveys, Toronto, Ontario

boatpoker being a member here. Along with a number of others as well. And some damned fine boat repairers & builders, who know loads about how boats are put together, what to look for when evaluating them, & of course, how to fix them.

Yes it was tested, hauled and surveyed on purchase. I just had no idea on the average sailboat speed and thought that the fouling didn't make that much difference. I would have had it done months ago if I'd known it affects performance so much.

[ryall]

Originally Posted by Dave22q

FIRST get a diver to scrape the hull and clean the prop. That will eliminate 90% of speed issues. Haul outs should be reserved for when you need them to repair something or repaint. Bottom cleaning about $100. Haul out $400+ any labor to do whatever. Boat speed is never a good reason to haul out.

Alright, I'll have a word with the marina and get some quotes. Thanks.

[psk125]

Originally Posted by StuM

Grrrrrrh!

How many times do we see this misconception repeated.

Do a forum search on the subject.

I stand corrected. The misconception may come from manufacturer's directives to lock the shaft to avoid transmission problems.

[Jd1]

Just to correct another misconception ..... you most certainly can strip paint with a pressure washer. You can strip it off a house, you can strip it off a car and you may very well strip antifouling paint although that is one thing I have not done yet and am not likely to try because of the possibility of stripping more then just the antifouling paint.

[knockabout]

are you against the incoming tide or current

[puffcard]

A foul bottom/prop is most likely your main reason for having the slows. You need a base line under power, smooth water, little to no current, no dingy and clean bottom. This was taken from a guy reviewing his Hunter 368, you need a baseline like that.

"The 40 HP Yanmar is powerful enough for push her along at 7+ knots when there is no current and our cruising rpms of 2400 she does a steady 5.5 to 6 knots with fuel consumption of about .7 or .8 gallons (2 litres or so) an hour."

Once you know you aren't dragging Sea World around, then you look at sail trim. You say jib trim is good, ok tail-tales are breaking evenly. I bet you have in the mast furling. The main has no roach, less sail area and power. You need to be very mindful of how your main is trimmed. Since you don't have any roach any twist in the main, where the main is riding up causes you to lose power. It takes a lot of work to control/trim roachless mains. Use the vang and traveler much more than the sheet. Also install a couple of tail-tales on the leach about 1/3 and 2/3 up. Get them both flying straight back and you are halfway there. +6kts is just around the corner

[desodave]

I suspect you have a similar Yanmar in your 386 to that in my 38, its successor model. Yanmar specifically says that the marine gear should be left in neutral when sailing with the engine off or marine gear damage will result.

[savoir]

It's probably a project for another day but start thinking about a folding prop. On a fin keeled boat a fixed prop will cost around 1/2 knot while sailing.

[ryall]

Originally Posted by savoir

It's probably a project for another day but start thinking about a folding prop. On a fin keeled boat a fixed prop will cost around 1/2 knot while sailing.

Definitely considering this, seems like it'd be worth it.

[ryall]

Originally Posted by desodave

I suspect you have a similar Yanmar in your 386 to that in my 38, its successor model. Yanmar specifically says that the marine gear should be left in neutral when sailing with the engine off or marine gear damage will result.

Yeah the 38 and 386 are almost identical from what I've heard. Good to know! Was this in the manual? I'll double check it in mine.

[UNCIVILIZED]

You can pick up a used folding prop in great shape for $150 +/-. And the difference is noticiable, but be aware that with a folding prop the boat won't handle quite so well when docking & doing other close quarters manuvering. As sometimes they're slow to fully open up in reverse, & or, don't develop nearly as much thrust in reverse as in forward, or when compared to a fixed bladed prop, or most of the feathering bladed ones.

[desodave]

Nothing in the manual Ryall. I too started sailing with the marine gear in reverse but became aware of a subsequent advisory from Yanmar in 2008, posted on another forum by Maine Sail. You can read it and view the discussion at
YANMAR - Gear Position While Sailing - SailNet Community
You can't get the gear back into neutral when sailing with it in reverse so have to start the motor with it already in reverse gear. 20,000 lbs of boat usually with some forward way on, and then a 40hp engine starting and trying to drive it in reverse at the same time. Bad physics

[desodave]

Hope that this isn't a second reply - it was a 2008 directive from Yanmar and not in the manual. I saw it in postings by Maine Sail at;

YANMAR - Gear Position While Sailing - SailNet Community
and at
Propeller gear for sailing | SailboatOwners.com Forums

The latter posting details the problems a bit more. I started out sailing my boat with the marine gear in reverse and it is impossible to shift it into neutral with any forward way on. If you think about the physics of a 20,000 lb boat with some forward way on countering a 40hp engine being started in reverse, it makes a lot of sense. Bad physics, especially for the drive train.

[donregan]

Originally Posted by Stumble

This is so far from what I would expect I have to ask, are you sure the GPS isn't reading VMG or speed to a mark? In 10kn I would expect at least 5.xkn.

Greg's comments are sensible. We have an older Hunter Legend 37 and it does at least that speed. We get 5.5 or so on SOG. Towing a dingy is good (bad?) for about -.5KT, leaving the tranny in neutral cannot overheat the engine - they are disconnected - might overheat the tranny on speed if you exceed hull speed but I doubt it without load, it w/b supported by 3 or 4 bearings.

Other advice on experiments and another sailor's knowledge also good.

Good sailing, Don