Stern Squat

[TortolaTim]

I just got my boat back in the water after moving to FL. Replaced standing rigging, new bottom paint, moved start battery aft, and switched to a new 3 blade prop. I motored 12 miles today in the river to my new slip and noticed the stern sitting low in the water. I ran below to make sure I wasn't taking on water, and thankfully, everything was dry. I think maybe the torque from the prop upgrade is changing the trim of the boat perhaps? I was running at 2500 RPM, 6-6.2 KTS boat speed, and the water was up to the bilge pump outlet on the transom, which puts the exhaust port under water. No fresh water in either tank, no extra weight astern. Has anyone ever seen this before? Is it a problem if the exhaust is under the water? There were 2 of us sitting on the stern rail seats too, but I've never noticed this before and we sit there all the time.

[Stu Jackson]

It's normal.

[waughoo]

This is normal based on my experience.

[Noah]

Normal depending on prop size and pitch that at high RPMs stern may bury. Be careful that you have high above water line loops on your bilge pump thru-hulls hoses so as to prevent backflow syphoning when buried. Been there done that!

[Bill Shreeves]

After my first season, this was my fifth, I replaced my 3-blade prop.  It had some fine cracks where the blade meets the hub and could not be repaired due to galvanic corrosion sometime in its life.  I replaced with a 10" pitch Michigan Wheel Sailor Prop over the previous 9" and I believe the stern squats more than it used to at higher RPM.   Especially when I run WOT which I do for 5 minutes or so about once a month to try and keep the bottom and prop growth down.  The boat definitely moves very well through the water and at WOT and it's pretty impressive how much get-up and go it has. My M25XPB has 26 HP over the original M25s @ 23 which helps but, not what the MK 1.5 or MLII have with their M35.

[Ron Hill]

Bill : I'm surprised the Black Dog Props (Kent Narrows) couldn't repair your old 3 bladed prop.  I still have mine pitched to 11"!!

Wish I could have installed a M35BC 35hp engine, But there was way too much cabinetry to change to fit that larger engine into a boat that was built for a 3 cylinder engine. 
People always look at us M25XPB engine owners and wonder why we didn't go for the larger engine ?? - simple, it just would NOT fit!!!

A thought

[Bill Shreeves]

Bill : I'm surprised the Black Dog Props (Kent Narrows) couldn't repair your old 3 bladed prop.  I still have mine pitched to 11"!!

Wish I could have installed a M35BC 35hp engine, But there was way too much cabinetry to change to fit that larger engine into a boat that was built for a 3 cylinder engine. 
People always look at us M25XPB engine owners and wonder why we didn't go for the larger engine ?? - simple, it just would NOT fit!!!

A thought

I used Atlantis Propeller near me in Cinnaminson, NJ.  They're pretty reputable and do the prop work for Cherubini Yachts.  They gave it a shot and said the material was too degraded to properly repair.  I can tell you it has a fair amount of pink discoloration in the bronze which I'm told is from the galvanic corrosion.  He said that it wasn't too bad and I could continue to use it but to carefully inspect it after each season for changes.  I felt I'd sleep better if I replaced it.  I'm hanging on it as an "emergency" prop.