Fresh water to Salt Water mods

Steve Moore

New Member
May 7, 2018
13
Boat Info
1987 Sundancer 300
Engines
twin Mercruisers 5.7L with alpha one drives
Hi all,

I have a 1987 Sundancer 300 currently located in the midwest where it has resided in a freshwater lake its entire life. I have moved to San Diego for work and would like to have a boat on the bay to enjoy. I am not getting much traction trying to sell it as it is a rather small market where it is located and i can't be there to "show" it to buyers. I need to decide between selling the boat cheap and taking a loss and saving to buy another boat here in SD, or shipping my boat to Cali and modifying it for Saltwater use. Any thoughts would be appreciated.

What mods would I need to do to make my Sundancer saltwater worthy?

Steve
 
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I had the same boat for years. It’s a pretty great boat. Mine lived in saltwater it’s entire life and still looked great when I sold her at 29 years old.
The environment is a bit harsher so you have to clean her more often. Make sure you hose her down with fresh water after a day on the water and the salt rinses right off. I also rinse the boat off with the hose on nice days even if I don’t leave the dock just to get any salt from the air off of it. No big deal.
You’ll also want to use Zinc anodes instead of aluminum if that’s what you use now.
If your motors are nice you may want to look in to putting fresh water cooling systems in them, Full systems will cost more and require seawater pumps being installed on each motor in already tight spaces. Might not be worth it.
But half systems would cover the motors and you would just need to be diligent about replacing the exhaust no more than every 5 years if you use OEM parts. Stay away from the aftermarket stuff. Not worth rolling the dice to save a few bucks.
I repowered mine when the starboard motor went bad at 25 years old and put half systems on the new motors.
BTW: I sold the good original 1987 raw water cooled motor to someone who put it in a 23’ Sea Ray and it is still running strong in 2019. All he did was clean up the exterior a bit, repaint it, install new exhaust and drop it in. He changed the exhaust again a couple of years ago.
 
Both my engines and lower/upper units were rebuilt in the last 3 years, so I would like to protect them. So a half system protects the engines but not the risers/exhaust, is that right? Any idea how much to install a fresh water cooling system? I was told I might also need new bottom paint to keep critters off of the hull.
 
Both my engines and lower/upper units were rebuilt in the last 3 years, so I would like to protect them. So a half system protects the engines but not the risers/exhaust, is that right? Any idea how much to install a fresh water cooling system? I was told I might also need new bottom paint to keep critters off of the hull.
Not sure about the cost of a full closed system but I lived and boated on the west coast for nearly 30 years with 18 of those in the LA/Orange county area.

You will definitely need to have the bottom painted with an ablative-type paint and you will most likely need a bottom cleaning service as well. This is typically a monthly service but often recommended every 2 weeks for boats with outdrives as the outdrives should not be painted with an ablative paint. You could also look into leasing a lift of some type.

I would consider a couple of other things.... You could ship your boat to San Diego and try and sell it there. Good clean fresh water boats bring premium dollars in Southern Cal. Also, if you are going to be boating offshore in the area you may want to consider a bit larger boat with inboards. Staying in SD Bay is nice but you may get the urge to explore up, or down the coast and you might enjoy having a bit more boat around you. Plus you won't have to deal with mid-west winters and you may be boating even more.

Best of luck to you. San Diego is an awesome place and you are fortunate to be able to live there. If you can stand the high cost of living and the liberal politics, the weather makes living there special. I miss it...
Shawn
 
Both my engines and lower/upper units were rebuilt in the last 3 years, so I would like to protect them. So a half system protects the engines but not the risers/exhaust, is that right? Any idea how much to install a fresh water cooling system? I was told I might also need new bottom paint to keep critters off of the hull.
Sounds like keeping and shipping your 300 might be a good choice if you are staying in boating since you know it’s history and the motors and drives are re-done.
Any boat you have in SD will require the exact same general maintenance so it may be best to invest in half systems on a boat you know than roll the dice on one you don’t.
I keep hearing guys here warning doom and gloom about outdrives in saltwater but we only have saltwater here and outdrives are very common.
My 1987 300 had the original drives on it when I sold it in 2016. The only thing I changed was the lower unit on the port drive and that was because I elected to swap it for a counter rotating one.
The Alpha Gen 2 Outdrive on my kids 2005 Maxum is original and it is also a saltwater boat.
Yes, you’ll need to paint your bottom.
Use an epoxy barrier coat if it has never been painted before. Interlux makes a good one that I used a few weeks ago on my Uncles boat after we had 20 years worth of bottom paint blasted off. It was easy to use.
I use an ablative bottom paint on the bottom and used another paint made for Outdrives on any that I’ve ever had.
You’ll need to leave about a 1 inch gap (mask off) between the outdrives and bottom paint. That small space will remain plain old uncoated fiberglass.
We have a 6 or 7 month season here so I have never had to have a bottom cleaned in the water or heard of anyone around here ever having to have it done during a season.
The routine around here is to re-paint the bottom (and drives) in the Spring before launch. Boat all season. Have the boat hauled in Fall. Bottom and running gear gets power washed when boat gets hauled out of the water for the winter.
Power washing is best done as soon as the boat comes out while it is still wet. I used to do my 300 myself. Had a boat hauler pull it out at a local ramp and block it on my property. The power wash took me about 30 minutes.
The boatyard where my 410 gets stored for the winter washes the bottom as soon as they have it on the lift.
We have guys around here who shrinkwrap, winterize, and store in the water over the winter then come out for a “short haul” in late Spring for a few days to wash their bottoms, bottom paint and detail.
I think the in water bottom cleaning thing by a diver is more prevalent in much warmer places (like Florida) with boats that may not leave the dock as often as others for one reason or another.
You’ll want to ask around where you’re dock will be to see what type of bottom paint is commonly used there and if they need in water bottom cleanings.
As far as pricing on half systems, you can take a look at MichiganMotorZ website. That’s where I got mine from.
Yes, you’re right. The half systems will only protect the motors and not the risers or manifolds.
For a full system you would need the auxiliary seawater pumps to be mounted on the motors because the little pumps in the Alpha Gen 1’s on your boat won’t provide enough to support them.
OEM Mercruiser E coated exhaust kits for your motors that include gaskets and new bolts can usually be found on the internet for about $600 each. So you would be looking at about $1200 every 5 years. Swapping them out is a relatively easy job for a DIY’er and take a few hours to do both motors start to finish.
 
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Half systems cost about 900 bucks per engine and are very easy DIY installs. Well worth the money if you know your engines are good.
 
I would recommend the full cooling system, you’ll only need to replace the risers every 5 years. Also replace the manifolds with the new style, dry joint. Sierra brand or Mercruiser if you have the extra cash
GLM, in my opinion are not good. Your risk on those, but had one that was porous and it took my freshly rebuild engine out.
By the way Souther California has 365 days of boating.
 
I would recommend the full cooling system, you’ll only need to replace the risers every 5 years. Also replace the manifolds with the new style, dry joint. Sierra brand or Mercruiser if you have the extra cash
GLM, in my opinion are not good. Your risk on those, but had one that was porous and it took my freshly rebuild engine out.
By the way Souther California has 365 days of boating.

I had an 87 300 Sundancer for many years. Bilge is a bit tighter than your Weekender and he doesn’t have auxiliary raw water pumps on his motors. His pumps are located in his outdrives.
The full systems are going to be a tight fit on a 300 Sundancer because they require raw water pumps to be mounted on the motors, once he got them mounted he would have an incredibly tough time getting to them to change the impellers in them every year. Probably have to do a lot of disassembly to get to them. The little pumps in his Alpha drives won’t support full systems.
 
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Sounds like keeping and shipping your 300 might be a good choice if you are staying in boating since you know it’s history and the motors and drives are re-done.
Any boat you have in SD will require the exact same general maintenance so it may be best to invest in half systems on a boat you know than roll the dice on one you don’t.
I keep hearing guys here warning doom and gloom about outdrives in saltwater but we only have saltwater here and outdrives are very common.
My 1987 300 had the original drives on it when I sold it in 2016. The only thing I changed was the lower unit on the port drive and that was because I elected to swap it for a counter rotating one.
The Alpha Gen 2 Outdrive on my kids 2005 Maxum is original and it is also a saltwater boat.
Yes, you’ll need to paint your bottom.
Use an epoxy barrier coat if it has never been painted before. Interlux makes a good one that I used a few weeks ago on my Uncles boat after we had 20 years worth of bottom paint blasted off. It was easy to use.
I use an ablative bottom paint on the bottom and used another paint made for Outdrives on any that I’ve ever had.
You’ll need to leave about a 1 inch gap (mask off) between the outdrives and bottom paint. That small space will remain plain old uncoated fiberglass.
We have a 6 or 7 month season here so I have never had to have a bottom cleaned in the water or heard of anyone around here ever having to have it done during a season.
The routine around here is to re-paint the bottom (and drives) in the Spring before launch. Boat all season. Have the boat hauled in Fall. Bottom and running gear gets power washed when boat gets hauled out of the water for the winter.
Power washing is best done as soon as the boat comes out while it is still wet. I used to do my 300 myself. Had a boat hauler pull it out at a local ramp and block it on my property. The power wash took me about 30 minutes.
The boatyard where my 410 gets stored for the winter washes the bottom as soon as they have it on the lift.
We have guys around here who shrinkwrap, winterize, and store in the water over the winter then come out for a “short haul” in late Spring for a few days to wash their bottoms, bottom paint and detail.
I think the in water bottom cleaning thing by a diver is more prevalent in much warmer places (like Florida) with boats that may not leave the dock as often as others for one reason or another.
You’ll want to ask around where you’re dock will be to see what type of bottom paint is commonly used there and if they need in water bottom cleanings.
As far as pricing on half systems, you can take a look at MichiganMotorZ website. That’s where I got mine from.
Yes, you’re right. The half systems will only protect the motors and not the risers or manifolds.
For a full system you would need the auxiliary seawater pumps to be mounted on the motors because the little pumps in the Alpha Gen 1’s on your boat won’t provide enough to support them.
OEM Mercruiser E coated exhaust kits for your motors that include gaskets and new bolts can usually be found on the internet for about $600 each. So you would be looking at about $1200 every 5 years. Swapping them out is a relatively easy job for a DIY’er and take a few hours to do both motors start to finish.

As I said, I boated in the LA/Orange County area for 18 years and trust me, you will want a bottom cleaning service. I don't know about other parts of the US but I do know the Southern Cal area.

Good luck which ever way you go.
 

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