Expected Performance by HP?

Captain Decent · Post by **Captain Decent** » Mar 11th, '19, 22:21

I was hoping to get a rough baseline of performance numbers for a given HP. I am shopping for Diesel powered boats.

I have seen anywhere between twin 170 to twin 370 configurations.

I don’t care about top speed much but I need to be able to cruise in the 20s. The higher the better.

Some boats we have interest in have one of 3 power packages: Yanmar 230,Cummins 250, Yanmar 315. We also looked at one with Volvo kamd 42 which have 230hp I believe but I’m apprehensive about those motors due to suspect reputation, high parts cost and the fact that the owner claims only a 17kt cruise which seems too slow for what i believe it should be capable of. Can anyone give me a rundown so I’m not wasting time on unsuitable boats? Thanks!

Tony Meola · Post by **Tony Meola** » Mar 11th, '19, 22:27

The Yanmar 230 and Cummins will give you a cruise up in the 20 Knot Plus range. I am running the 270 Cummins and once I got the props right cruising at 24 knots is not an issue. She tops out just shy of 30 knots. The 250 Cummins will give you almost the identical performance as the 270.

mike ohlstein · Post by **mike ohlstein** » Mar 12th, '19, 10:42

170 HP is not enough for this boat, unless you're never leaving the bay or don't care about cruising above 18 knots.

Yanmar 230/240 cruise is 23 or 24. Yanmar 315 cruise is 27 or 28. Almost nothing is simpler to maintain than a 6BT. They pretty much run forever in the 250 to 330 HP range and will give you similar performance numbers as the 315 Yanmar. Shaft angle and prop clearance being what they are, without making the enormous mistake of adding prop pockets, adding additional HP is simply a waste of time for a variety of reasons.

Carl · Post by **Carl** » Mar 12th, '19, 14:35

230hp should give better performance then 17knts.
Although I'm far from a Volvo fan.

From my understanding 6Bt's at 210hp will give a 20-21 knot cruise.

20knts

Not fast enough to be considered fast...but fast enough not to be considered slow.

Yannis · Post by **Yannis** » Mar 13th, '19, 12:26

Great, Carl, great definition of speed!

Amberjack · Post by **Amberjack** » Mar 13th, '19, 16:28

I reduced the props on Amberjack last year to reach a WOT of 3900 rpm so we're still dialing in the results but here from memory is what I recall from the speed chart I'm building:

Yanmar 6LP-STP 850 hours

2500 rpm 22 knots slow cruise
3000 rpm 25 knots very comfortable fast cruise
3900 rpm WOT so fast the boat was jolting too much and I couldn't read the gauges
fuel consumption at any speed between 2500 - 3100 rpm is 1.65 nm/gal

I've also read good things about the Yanmar 240's. Perhaps slightly underpowered for a B31 but good reliability and good fuel economy. If you keep the boat light without a lot of genset, AC and fishing tower stuff they will work well. Pay attention to maintenance records because they give an idea of the future service life of the engine and modern rebuilds are expensive. The longtime Yanmar 6LP mechanic I use says they start to see my model for major service after about 1800 hours but that average includes bad owners as well as careful owners. I'm halfway there but I take good care of mine and hope they outlast me.

EarleyBird · Post by **EarleyBird** » Mar 14th, '19, 05:01

With the 4th set of motors in the boat presently with over 4000hrs.in a,1973 FBC, I now have 5.9bta Cummins 270HP. Maximum RPM is 2600. Running at 2300, full load, 220gallons/fuel, 4 adults, ice,bait,etc overnight Offshore trip (80 miles one way)she runs plus or minus 24kts. 1 1/2” shafts, 20x22 4 blade DQX props. She’ll burn 150 gallons of diesel, plus or minus 10 gallons, generator all night. On the way home next afternoon less 100 gallons at almost 2400RPM she’ll touch 27 occasionally. Gotta be a nice trip home...ie flat calm. Maintenance wise, they ARE the simplest to work on, parts are readily available and not costly out of sight. Trust me, I have worked on them all,Volvo’s, Cats, and Yanmars. Get a set of Recon 5.9 Bta 270 hp Cummins with 220A ZF Gear’s, you will not be disappointed. There are many 31’s in the Pt.Pleasant NJ (Caver Boat Sales) with that same package.

Carl · Post by **Carl** » Mar 14th, '19, 06:32

Amberjack wrote: I've also read good things about the Yanmar 240's. Perhaps slightly underpowered for a B31 but good reliability and good fuel economy.

I understand the point...but whats funny is these boats came from the factory with 4-53's GM diesels at 130-140hp back in 60's.

Then for more performance the V504 Cummins at 195hp were offered. Low hp, big, heavy iron...
Now today we consider a light, 240 HP diesel as "slightly under powered".

Amberjack · Post by **Amberjack** » Mar 14th, '19, 13:33

I understand the point...but whats funny is these boats came from the factory with 4-53's GM diesels at 130-140hp back in 60's.

Then for more performance the V504 Cummins at 195hp were offered. Low hp, big, heavy iron...
Now today we consider a light, 240 HP diesel as "slightly under powered".[/quote]

Good observation Carl and as usual with you, on point. At 630 total hp I feel Amberjack is overpowered and my wife comments that it is a hull wrapped around a pair of engines and a fuel tank. Diesel power in the range of 220-280 hp is plenty adequate for our Bertram 31's. But on the couple occasions when I had to hammer the throttles I was grateful for the extra hp.

Carl · Post by **Carl** » Mar 14th, '19, 19:05

Amberjack wrote: At 630 total hp I feel Amberjack is overpowered and my wife comments that it is a hull wrapped around a pair of engines and a fuel tank. Diesel power in the range of 220-280 hp is plenty adequate for our Bertram 31's. But on the couple occasions when I had to hammer the throttles I was grateful for the extra hp.

630 hp diesels is overpowered, but I'd much rather be over then under.

SteveM · Post by **SteveM** » Mar 14th, '19, 20:22

I have Yanmar 315's. Numbers similar to Amberjack. They've been good. One reason I went with them over Cummins was because where I boat in the Bahamas there are two Yanmar service centers. They seem quieter than Cummins to me. I hope they last me a long time.

Cummins have a great reputation and probably the most common diesels to install in this boat, or any other in this size range for that matter. And there are parts and service centers just about everywhere.

Captain Decent · Post by **Captain Decent** » Mar 14th, '19, 20:43

EarleyBird wrote:With the 4th set of motors in the boat presently with over 4000hrs.in a,1973 FBC, I now have 5.9bta Cummins 270HP. Maximum RPM is 2600. Running at 2300, full load, 220gallons/fuel, 4 adults, ice,bait,etc overnight Offshore trip (80 miles one way)she runs plus or minus 24kts. 1 1/2” shafts, 20x22 4 blade DQX props. She’ll burn 150 gallons of diesel, plus or minus 10 gallons, generator all night. On the way home next afternoon less 100 gallons at almost 2400RPM she’ll touch 27 occasionally. Gotta be a nice trip home...ie flat calm. Maintenance wise, they ARE the simplest to work on, parts are readily available and not costly out of sight. Trust me, I have worked on them all,Volvo’s, Cats, and Yanmars. Get a set of Recon 5.9 Bta 270 hp Cummins with 220A ZF Gear’s, you will not be disappointed. There are many 31’s in the Pt.Pleasant NJ (Caver Boat Sales) with that same package.

Your comment about carver boat sales, are you saying they have some for sale? I am shopping and looking for any and all candidates. I have found a couple on boat trader and/or yacht world but want to make sure I exhaust all options!

The one we really like is just beyond our price range when you add on taxes and transport across the country. Found a couple others that look promising but don’t want to settle either.

EarleyBird · Post by **EarleyBird** » Mar 14th, '19, 20:58

None for sale that I know of now at Carver’s. There are several in the boatyard, with Cummins power packages like I spoke of and identical to mine. They converted several years earlier. I know of one for sale, in another yard,the Bahia Mar model, drive by it everyday. She’ll need a lot of TLC to make her right. It’s located at Forsberg Boatworks, Beaver Dam Rd.in Pt. Pleasant.
EarleyBird

Tony Meola · Post by **Tony Meola** » Mar 14th, '19, 20:59

Are you looking for a Fly bridge model or a Bahia Mar style?

Take a look at some of the posts in the sale area of this board. We have a couple of members looking to sell. You will see them posted as for sale or you might find a post in one of the threads of someone looking for a 31.

Captain Decent · Post by **Captain Decent** » Mar 14th, '19, 22:17

Tony Meola wrote:Are you looking for a Fly bridge model or a Bahia Mar style?

Take a look at some of the posts in the sale area of this board. We have a couple of members looking to sell. You will see them posted as for sale or you might find a post in one of the threads of someone looking for a 31.

Flybridge is what I’m looking for

Charlie J · Post by **Charlie J** » Mar 15th, '19, 05:07

i had the yanmar 230s
i would cruise at 22kts
and wot would hit 30 kts
all 3 of thous engines you cant go wrong
yanmar 230, 240, 315
or cummins
i was running a bahia mar

bob lico · Post by **bob lico** » Mar 27th, '19, 21:07

Very interesting how the same boat can have different performance curves with similar power plants.i have 315 hp Cummins that have set a new personal record for mechanical devices. Some years ago i had a Toro lawnmower that went 12 seasons without a single repair well the cummins are in there thirteen season with 0 repairs. remarkable !!!!!!! cruise all day at 29 or 30 knots with incredible fuel economy but will drag and run terrible in flat water, it needs a minimum of two foot waves to get up on inner strakes. the boat also feels like i am towing another boat at 13 to 20 knots actually came down off bridge to check bilge for huge water leak like broken hose even with no alarms going off. the boat literally pops out of water when you hit the bottom of power curve (2100 rpm)and will pull like crazy all the way to WOT.actually it comes down to the fact that a pair of Cummins with outside air supply have double the torque of a pair of 230hp Yanmars and if you don`t prop it to take advantage of that torque you are just spinning your wheels.

Tommy · Post by **Tommy** » Mar 28th, '19, 14:59

I found the performance curve on Island Girl after Bruce and Patrick repowered her back in 2001:

1973 Bertram 31 Sportfisherman; Bimini Top; 220 gallons fuel; 2 people; moderate amount of gear on board; winds light and variable
Yanmar 6LPSTE 315 HP, Max rated RPM 3800; continuous cruise @ 3600 RPM; Preferred cruise 3000-3200 RPM
Hurth ZF Transmissions HSW63OA; Port 2.10:1, Stbd 2.04:1
20 X 24 bronze 4-blade props

RPM Knots
700 5.1 (idle)
1200 7.6
2000 13.7
2400 19.0
2600 21.2
2800 22.9
3000 24.9
3200 26.7
3400 28.0
3600 29.6 (Maximum continuous operating RPM)
3800 31.5 (Maximum recommended RPM per Yanmar)
4000 33.0 (WOT; Bruce propped the boat to exceed 3800 when light so it would still hit 3800 under a full load)

Yannis · Post by **Yannis** » Mar 30th, '19, 01:12

Tommy,

I have very similar, if not identical figures for my 28 with Yanmar 240's up to 3000rpm. Then wot is at 3300 and 31 knots.
Would you know which of the two, 28 or 31, is heavier?
I know the 31 can carry much more fuel, but liquids excluded, how do they compare?
Thanks.

Amberjack · Post by **Amberjack** » Mar 30th, '19, 12:34

Yannis--The factory listed 31's at 10,300 lbs with gas power. Presumably that is right out the door with no fuel, or other added weight. I've never been able to get an accurate weight on mine as it is presently configured. The weight gauge on every comporter that has lifted Amberjack has been either broken or gave wildly improbable figures.

Tommy--That 3600 continuous rpm looks awfully high. I've been using 80% of WOT (3,040 rpm) as the rule of thumb for my Yanmar 315's. Be interesting to hear what others think.

Yannis · Post by **Yannis** » Mar 30th, '19, 23:17

Thank you Doug.

I just had my annual service and my mechanic told me that I can run my 240’s which have a wot of 3300, at 3000 without any problem. This is what I do anyway. This is only 10% less than wot, actually Yanmar even suggests that the max continuous rpm is 3100. For the 315, which have a wot of 3800, if you follow the same logic, the max continuous should be around 3400 (?). But, there are more than one 315’s, I dont know if that has a repercussion on rpm’s too.
Our engines run with new oil every year, so that for the 30-40 hours I put in every season, this means that these motors always run on clean oil.

bbtiller · Post by **bbtiller** » Mar 31st, '19, 09:37

I have 250hp cummins, 6BTA, 26kts at 2300rpm, rated cruise as I understand is 2400, wot is 2600.

Tony Meola · Post by **Tony Meola** » Mar 31st, '19, 21:35

bbtiller wrote:I have 250hp cummins, 6BTA, 26kts at 2300rpm, rated cruise as I understand is 2400, wot is 2600.

26 knots seems high for those engines. How light are you running? I have the 270's with a Fly bridge Cruiser and I am around 24 knots at 2300 RPM's. Will run faster as she gets lighter on fuel.

Craig Mac · Post by **Craig Mac** » Apr 1st, '19, 07:25

I was on the Blackfin site and came across a performance data chart that was started---I think we should have one as well.

As usual ---I am not able to add the attachment--here is the address

http://www.blackfinforums.com/content/props-4

the chart was posted on March 29

bob lico · Post by **bob lico** » Apr 1st, '19, 08:08

i agree 26knt. at 2300 rpm would indicate a super light Bahia Mar or moppie unless you really put time into different props. and changed shaft angle together would extreme hydrodynamics to running gear. Give us a photo or more information.

Craig Mac · Post by **Craig Mac** » Apr 1st, '19, 08:53

looks like you need to be a member on the blackfin site to see the chart----I can send a file to anyone that can post it here.

Tommy · Post by **Tommy** » Apr 1st, '19, 10:51

Yannis, according to the old spec books, the B-28 out the door weighs 11,320 # for the SF model and 12,060 # for the FBC model. On one of the spec sheets I found, the B-31 SF and FBC are recorded as 10,600 #. I'm thinking the weight difference is a result of Bertram providing more creature comforts in the cabin of the 28 model.

Amberjack, I agree with you that a continuous operating RPM of 3600 on the 6LP-STE sounds high, but it's in the specifications in the owners manual (link below) With that said, I'm like you and chose to run mine in the 3200 RPM range.

http://www.marx-ftp.de/Downloads/Marine ... chnung.pdf

Yannis · Post by **Yannis** » Apr 1st, '19, 12:35

Thank you Tommy.

Captain Decent · Post by **Captain Decent** » Apr 1st, '19, 21:40

Well I ended up putting a deposit on a 31 with Yanmar 315s. Sounds like I’ll be in the mid to high 20s which works just fine for me.

Carl · Post by **Carl** » Apr 2nd, '19, 08:36

Captain Decent wrote:Well I ended up putting a deposit on a 31 with Yanmar 315s. Sounds like I’ll be in the mid to high 20s which works just fine for me.

Best of luck with it!
A Great boat with great iron.

bbtiller · Post by **bbtiller** » Apr 2nd, '19, 18:52

bob lico wrote:i agree 26knt. at 2300 rpm would indicate a super light Bahia Mar or moppie unless you really put time into different props. and changed shaft angle together would extreme hydrodynamics to running gear. Give us a photo or more information.

I'm not that light, FBC, with genset, A/C, 30gal water, Head, holding tank, hotwater heater, hardtop...you name it. I'm not lyin', 26 at 2300. Probably half full of fuel though.

EarleyBird · Post by **EarleyBird** » Apr 2nd, '19, 19:25

I believe your last sentence verified your speed. Take 110 gallons out of a 220 gallon tank and you just became OVER 700 lbs. lighter AFT. Put all your gear in the V-berth and you might even gain another 1/2 kt. 26kts. @2300rpms, you got her dialed in Capt.
EarleyBird

Yannis · Post by **Yannis** » Apr 3rd, '19, 08:40

Earley bird—- my cousin who is a naval architect explained to me that if you wish to obtain optimal speed and economy in a planing hull, then you should make sure ALL weights are as aft as possible. I wonder why you’re suggesting the opposite...Of course I cannot be a judge of right or wrong in this argument as I lack all pertinent technical knowledge.

On another note, I looked into what Tommy posted, namely the Yanmar manual for the 315. In it, there appears a fuel consumption figure of 180g/hp/hr.
I recall some almost 40 years ago in my island, there was a guy who was good at almost everything...he could build from houses to boats, passing from jewellery in his slack. A very tallented person. Anyway, at that time he was building a boat and was doing the calculations for the size of the diesel tank. He made all calculations based on his knowledge that all diesel engines burn 170g per hp per hr, and that was 40 years ago! I wonder, has there not been any evolution in the meantime to bring down that figure? Where is all the economy that newer motors are so notorious for? Where is the technology of 4 decades gone? Beats me.

EarleyBird · Post by **EarleyBird** » Apr 3rd, '19, 18:45

Well Yannis you have succeeded in getting a rise out of me. I have a 1973 FBC with 270HP Cummins...4000 plus hours, that I have owned since August 1986. Canyon fish (80 miles plus one way). Your Naval Architect brother may be right..in theory. In reality that boat or any other 31 Bertram with 250HP Cummins will not,fully loaded,fuel and all,do 26kts.@2300rpmz. It ain’t happening. Lighten her up,(less over 100gallons/fuel)clean bottom,flat ass calm, hi-Tech propellers you might with a following wind and sea do 25plus. I’ll even give you Trim Taps,to lift her rear end up! Which,oh yeah, I do not have. Your turn?

Tony Meola · Post by **Tony Meola** » Apr 3rd, '19, 20:26

I have to agree with Early Bird. I have the same engines as he does. First launch after repower we got 22 knots at 23 knots at 2300 RPM's. When we pulled the boat for the winter we tweeked the props and now we are 24 at 2300 RPms, and most of my weight is aft with a full tank. Once I hit a half a tank she climbs up to 25 and 26 knots depending on the current, wind etc.

If someone has the same boat as me and is turning 26 knots at 2300 RPM's I want to know what props he is turning. Size and how much cup and style. I would love to have 26 knots at 2300 RPM's. That would mean I could dial her back 100 to 200 RPM's and still run 24 knots and save a ton on fuel. I am running light also, no tower or excess weight.

The nice part of the Cummins is they take a lot of extra weight before the speed drops off.

EarleyBird · Post by **EarleyBird** » Apr 3rd, '19, 21:20

Your right on Tony. The EarleyBird is turning 1 1/2” Aquamet 22 shafts. 83 1/4” EOT. Originally Hy-Torq 20X22 4 blades,#7 cup. At 2300 rpms fully loaded heading East,24 kts.we’d all be smiling. I splurged bought a set of 20X22 4 blade DQX wheels with a medium cup and at the same RPMz 2000 and above she gained another knot plus at same RPMz. At the pins, full load of fuel, 220gallons(original tank) with just me she has NEVER hit 30....29plus never 30. Like I said earlier 150 gallons plus or minus 10 on an overnighter. 80 there and 80 home. Jim EarleyBird

bbtiller · Post by **bbtiller** » Apr 4th, '19, 13:43

Tony Meola wrote:I have to agree with Early Bird. I have the same engines as he does. First launch after repower we got 22 knots at 23 knots at 2300 RPM's. When we pulled the boat for the winter we tweeked the props and now we are 24 at 2300 RPms, and most of my weight is aft with a full tank. Once I hit a half a tank she climbs up to 25 and 26 knots depending on the current, wind etc.

If someone has the same boat as me and is turning 26 knots at 2300 RPM's I want to know what props he is turning. Size and how much cup and style. I would love to have 26 knots at 2300 RPM's. That would mean I could dial her back 100 to 200 RPM's and still run 24 knots and save a ton on fuel. I am running light also, no tower or excess weight.

The nice part of the Cummins is they take a lot of extra weight before the speed drops off.

I'm turning 3 blade wheels but don't know the particulars, I'll try to find that out.

Tony Meola · Post by **Tony Meola** » Apr 5th, '19, 22:27

3 Blade wheels normally give you a lower cruise and a higher top end.

Let us know what you are spinning. The biggest wheel most with the Cummins spin is 21 inch diameter. So if you are spinning anything under 20 inch's you wuld of had to of added ton of pitch or cup in order to not over rev the engines on the top end.

I hit 2650 RPM's wide open, and like Jim said just shy of 30 knots with a full load of gas.

bob lico · Post by **bob lico** » Apr 28th, '19, 16:25

on the calculator, 78% power will make 27 to 28 knts. fuel economy is exactly the same as 26' regulator with twin 150hp yamahas however i can go in the cabin, sleep,make coffee,and heat up a bucket of KFC.and sit at a table and read the papers or i can i take a dump in a porcelain toilet. wot is 34 knots with the "high cruise PROPS" fully loaded for offshore fishing.

Tony Meola · Post by **Tony Meola** » Apr 28th, '19, 20:59

Bob

Yes but you have higher HP engines, changed the shaft angle and other things. They are talking lower HP engines.

bob lico · Post by **bob lico** » Apr 28th, '19, 22:24

higher HP. yes but cruising at much lower rpm for maximum fuel economy and on a long term engine longevity running 22% off the pins.

bbtiller · Post by **bbtiller** » Aug 26th, '20, 14:21

Back to this since I recently had to have my starboard prop replaced (slung a blade) this is with 21 x 23 3 blade props. Had the port prop tuned. Prop guy said there is a little cup in them also. (Big Rock Propellers in Morehead). That was running down the bay at slack tide...just over 2300 rpms. 26.3kts. On the way offshore...7/8 tank of fuel, 200lbs ice and 4 grown men, 25 gal water, tackle, bait, etc. Offshore we made 24.5kts at 2200 in a calm sea.

If the photo doesn't show up go to the imgur link here: https://imgur.com/mDUzJKo

Carl · Post by **Carl** » Aug 26th, '20, 14:50

bbtiller wrote:Back to this since I recently had to have my starboard prop replaced (slung a blade) this is with 21 x 23 3 blade props. Had the port prop tuned. Prop guy said there is a little cup in them also. (Big Rock Propellers in Morehead). That was running down the bay at slack tide...just over 2300 rpms. 26.3kts. On the way offshore...7/8 tank of fuel, 200lbs ice and 4 grown men, 25 gal water, tackle, bait, etc. Offshore we made 24.5kts at 2200 in a calm sea.

If the photo doesn't show up go to the imgur link here: https://imgur.com/mDUzJKo

well kinda tough to dispute those numbers with a picture of tach and plotter. Nice!

I just picked up the same Simrad unit. How do you like? What transducer are you using? I bought mine in a pinch and using supplied transom mount dropped into the bilge sitting in a bag of water till I decide how to move forward.

My choice was limited to hhmmm, you have this one in stock and non of the others...I need a depth finder now, I guess I'll take that one. Actually a pretty nice unit so far...just wish it connected to my flush mount angled transducer.

Tony Meola · Post by **Tony Meola** » Aug 26th, '20, 21:05

Carl

Did you check to see if there was an adapter? I have been told you can match up different brands with an adapter.

Carl · Post by **Carl** » Aug 26th, '20, 21:30

Thanks Tony I have looked, Airmar said Simrad don't play nice like the other companies...

I'll continue to look though...make some more calls. Looks like I can get the Simrad blue adapter...just not the Hook Simrad is now using on this model. Normal story of my life...

bbtiller · Post by **bbtiller** » Aug 28th, '20, 11:32

Carl,
I like the Simrad, but don't have a transducer installed for it...yet. I have a furuno 588 but plan to add a transducer to this Simrad. Have been researching and would appreciate input from the sandbox.

Tony Meola · Post by **Tony Meola** » Aug 28th, '20, 23:57

Bradley

I would say it depends on which model simrad and do you want to use all of the capabilities. If side scan is not an issue send you only want to use the chirp feature as an example, then I would lean towards a flush mount airmar.

Carl · Post by **Carl** » Aug 29th, '20, 06:34

Tony-

It's the Cruise model, looks like the 9. No side scan and they use a proprietary Hook 2 connection for the transducer. So far the only adapter I have been able to find is for their sister company lowrance units known as the blue connectors. Seems theirs transducer are navicular and not Airmar. Figures as I pulled out all my older transducers and installed a nice 21°flush mount Airmar. I called them to ask about adapters and in short they told me the Simrad Cruise modal are built not to play nice with others. I spent some time looking online for adapters...came across one that adapted to the blue and one that goes from blue to...
...at that point I decided to just use the supplied transducer, mount inside hull in an RV coolant bath and see how I like. I have too many other loose ends to occupy my time right now. Maybe when I get around to serious fishing a better answer will present itself.

Yannis · Post by **Yannis** » Aug 29th, '20, 09:17

While you guys are at it, what do you suggest for a 7 or 9 inch max chartplotter?
No fishfinder.
I don't want to spend big money. My 7 inch simrad is very near the trash can actually...

PeterPalmieri · Post by **PeterPalmieri** » Aug 29th, '20, 12:07

Yannis wrote:While you guys are at it, what do you suggest for a 7 or 9 inch max chartplotter?
No fishfinder.
I don't want to spend big money. My 7 inch simrad is very near the trash can actually...

The Garmin GPSMAP 722 is a nice unit for your needs if you don’t want radar or sonar

https://buy.garmin.com/en-US/US/p/56165 ... 0-01738-00