how to get to plane

joanwillison · Post by **joanwillison** » Thu Apr 07, 2011 3:34 pm

We have a 31/32 foot 1967 Trojan cruiser. How fast do we have to go in order for her to plane? We do have Bennet Trim tabs. We just aren't that experienced. Any info appreciated.

Stripermann2 · Post by **Stripermann2** » Thu Apr 07, 2011 6:24 pm

Okay, well...without knowing your engines and how clean your hull, running gear is, I'll tell you what works for me.

I start out with no tabs, bring both engines up to about 2800 rpms. At this point I can start with tabs, bring the bow down until I find that spot where my speed and attitude of the boat rides best.

Once I'm cruising about the speed I want, I make adjustments to tabs and if I have to bring throttles back a bit, I do. Ya can't firewall the throttles, trying to get on plane...that would be a sure way to shorten your power plants.

Nice and gradual is what I find best.

k9th · Post by **k9th** » Thu Apr 07, 2011 8:19 pm

First of all, welcome to the forum.

I agree - smooth and steady acceleration usually does the trick. My '79 literally pops up on plane with very little effort.

captainmaniac · Post by **captainmaniac** » Thu Apr 07, 2011 8:35 pm

Or an alternative approach to Stripermann ... tabs down full, slowly increase throttle. Around 2000 rpm you will be just climbing up on plane (at least that was the threshold on my father's '69 28footer, but he also only had single engine so yours may be a bit different). With the tabs down, it will keep the bow down as low as possible so you can see better while climbing up, plus will help you jump up on plane a bit faster.

At that point you will be just on plane, and fighting to stay there. As you increase speed beyond that, bring the tabs up bit by bit. Just use a 'tap-tap' technique on the controls and wait for the boat to respond - it takes a few seconds (say 5-10) for things to react and a new equilibrium to be established after a change in tab settings. If you push and hold for 2-3 seconds when making adjustments you will never get it dialed in.

At a given speed, if tabs are down too far you will feel the bow digging in, spray coming up way forward, and feel some bow steer. If tabs are too high you will have harder time seeing over the bow, and may start to fall off plane again (you will see your speed drop). As you play with them up and down, it won't take to long for you to find a setting that just 'feels right'. The boat will be riding smoother and feel more free and under control. At a given engine speed (rpms), if you tweak the tabs and boat and engine speed increase, you are going in the right direction (less drag means less work, means easier running).

Your 'sweet spot' for faster cruising should be around 2800-3200 RPM, and you should probably get about 16-20 knots out of it when properly trimmed. I think we used to get about 15knots at 2500rpm, then about 1 knot per 100 rpm increase from there through the power band.

alexander38 · Post by **alexander38** » Thu Apr 07, 2011 9:00 pm

+1 on the Capt.

rossjo · Post by **rossjo** » Thu Apr 07, 2011 10:20 pm

18mph

joanwillison · Post by **joanwillison** » Fri Apr 08, 2011 8:55 am

Thanks for all of your advice. I guess we tend to putt along because it seems hard to believe that running that fast is more efficient and easier on gas. I will put it to the test when the boat goes in the water in May. Can't wait.

rossjo · Post by **rossjo** » Fri Apr 08, 2011 9:08 am

Planing is not most efficient (better than plowing at 12-15 knots).

Hull Speed is most efficient.

For your boat (WL =~ 30'), that is 7.5 knots (~8mph).

http://www.sailingusa.info/report_speed.htm

joanwillison · Post by **joanwillison** » Fri Apr 08, 2011 9:28 am

Hull speed it is then. I always thought that that was the reason for getting on plane - for efficiency. ?????

rossjo · Post by **rossjo** » Fri Apr 08, 2011 11:30 am

Getting on plane is to get the thrill of speed !

It IS more efficient than plowing along between hull speed and planing speed (like many Sea Ray owners do).

Met a Methodist minister who had retired and just done the Great Loop in 1 year with his wife on their 50' Grand Banks (guess ministers make more than I though).

We got up and had coffee with them in the morning (adjacent boat in Georgetown, SC).

A big SeaRay plowed by throwing a huge wake. He waved his arms at the guy, who simply waved back. I shook my head.

The Methodist Minister turned to me and said, "Do you know what SeaRay stands for?"

I smiled and said no.

He said ...

"
Stupid
Egotistical
Arrogant
Really
Awful
Yachtsmen
".

I'll never forget it - or the burning coffee coming out of my nostrils!

joanwillison · Post by **joanwillison** » Fri Apr 08, 2011 11:48 am

Rich minister - 50 feet power boat. Happy I don't have a Sea Ray, ours is a Trojan, 1967. Sweet.

I won't be planing - my husband doesn't like to go fast. I hate to think it but I guess we are plowers, although I always slow right down near other boats because we throw a big wake, so we are polite plowers.

Stripermann2 · Post by **Stripermann2** » Fri Apr 08, 2011 12:00 pm

Ross, around here, we just call them Sea Rats...

foofer b · Post by **foofer b** » Fri Apr 08, 2011 7:25 pm

rossjo wrote:
(guess ministers make more than I though).

Not necessarily, they probably just spend less on booze and broads!!

rbcool · Post by **rbcool** » Sat Apr 09, 2011 8:31 am

(A big SeaRay plowed by throwing a huge wake. He waved his arms at the guy, who simply waved back. I shook my head. )

Sorry bout that Ross..... My doggie needed to find grass

Ron

prowlersfish · Post by **prowlersfish** » Sat Apr 09, 2011 10:15 am

joanwillison wrote:Rich minister - 50 feet power boat. Happy I don't have a Sea Ray, ours is a Trojan, 1967. Sweet.

I won't be planing - my husband doesn't like to go fast. I hate to think it but I guess we are plowers, although I always slow right down near other boats because we throw a big wake, so we are polite plowers.

If your throwing a big wake you maybe going over hull speed , keep it below 8 mph and you save fuel . fuel burn goes up fast above hull speed