Comments for BoatHowTo

Comment on Raw Water Cooling Systems by A.G. Breitenstein

A.G. Breitenstein — Wed, 29 Jul 2026 18:03:53 +0000

We have a catamaran with two Yanmar 57s. I noticed that the manual advises closing the raw water seacock when running only one engine. Our engines are above the water line. Do we need to follow this guidance? I’m very hesitant to close that raw water seacock for fear of forgetting to open it (or having an emergency where we need the engine on quickly). How serious a warning is this? Would a siphon break alleviate the need to close that seacock?

Comment on Oil Change by Paul Andrews

Paul Andrews — Wed, 29 Jul 2026 16:24:25 +0000

I have a Yanmar 4JH3-TE engine on my sailboat, which has 3800 hours on it, 2000 hours are my use.
Ever since I purchased the boat, most often when I initially pull the dip stick out, it is dry or only has a small amount of oil on the very bottom of the dip stick. I clean off the dip stick and wait about 15 seconds and put the dip stick back, wait several seconds and pull it out again to read the level. This time there is oil at an expected level, between the high and low marks.
Is this common? Or is this a sign of a problem?

Comment on Basic Circuits by Jan C. Athenstädt

Jan C. Athenstädt — Wed, 29 Jul 2026 09:53:39 +0000

In reply to tamayson49@gmail.com.

Hi Tom,
This looks correct!
Jan

Comment on Transmission Configurations by Corey Small

Corey Small — Tue, 28 Jul 2026 18:54:27 +0000

Nigel,

When I crew on 30-ft racing sailboats with two-blade folding propellers, we often put the marine gear in reverse while racing, ostensibly to keep the prop from rotating and allow it to fold.

What do you think about this? Is it safe for the transmission? Would you ever leave the gear in reverse while under sail power with a non-folding propeller?

Comment on Bonding & Cathodic Protection by Denis

Denis — Mon, 27 Jul 2026 19:24:43 +0000

Hello Nigel & Jan,

I’m going to use the cast-iron keel of my sailing boat as a ground, as I’m going to fit a flexible coupling for the shaft line of my inboard engine. My question is: should I protect the sailing boat’s cast-iron keel with an anode?
Thanks for everything – your courses are brilliant!
Denis

Comment on Transmission Configurations by Michael McManus

Michael McManus — Mon, 27 Jul 2026 19:06:00 +0000

Should Basic “Cone” Marine Gears and Complex Z Drive Marine Gears be covered/mentioned as well ?

Comment on Basic Circuits by tamayson49@gmail.com

tamayson49@gmail.com — Sun, 26 Jul 2026 22:41:14 +0000

Good afternoon
I have been stuck on the parallel and series example with the 25W and 10W resistances. Specifically, when starting the calculations for the series, the resistance from the parallel system was dropped into the series system (14.5 +5.8 = 20.3 ohms). This, to me was mixing apples and oranges. So, I did my own calculations.
Formulas for a Series

V1 + V2 = VT R1 + R2 = Rt AmpsT = A1 = A2 W = V× A

W1= 25 W2 = 10
W1 = V1×A W2 = V2×A
25/V1= A 10/V2=A
25/V1=10/V2 where: V1=24-V2
25×V2=10V1
2.5V2 = V1
2.5V2=24 – V2
3.5V2 = 24
V2 = 17.14V
V1 = 6.86 V
A similar answer as shown in the lesson. Would you please comment on my calculations.

Comment on Air Supply by Corey Small

Corey Small — Sun, 26 Jul 2026 20:28:52 +0000

Greetings,

What are some of the factors that make volumetric flow rate difficult to estimate for turbo diesels? Can no general advice be given?

Comment on Turning Light into Electricity by Nigel Calder

Nigel Calder — Sun, 26 Jul 2026 18:44:52 +0000

In reply to Andrew Wedekind.

Andrew,

That’s an interesting question! So far, the only installations I have seen have been rigid panels mounted without a reflexive surface beneath them, so I am guessing the efficiency gains have been very limited.

To achieve maximum gains, you want an airspace and a white, reflective surface. When you think about this, it severely limits the application on most of our boats. I may be wrong about this, but I think the jury is still out!

Nigel

Comment on Changing Secondary Filters by Nigel Calder

Nigel Calder — Sun, 26 Jul 2026 18:29:44 +0000

In reply to Corey Small.

Corey,

This is not uncommon!

Nigel