New to Motor Boating in Croatia

[BartW]

with the small boat, I alway's moore bow to, (all small boats do it there)
and use the "bow" or "ground" rope thats is sometimes there for the big boats,
use that as a stern line,
like on the picture in Kobas

if that rope is not there, like in Cavtat on the main quai,
if its for a short stop I drop a ketch anker, 20-30m behind the boat
the big boats drop their main anker 50m..100m in front of the quai

and in some occasions, like Dubrovnic old harbour, i found a place that is usually free, and fix my stern on the neighbour boat, after asking the owner who was there at one occasion, (similar boat size)
have used that spot many times, will post a picture one day...

 

[pred02]

It would be easier to moor bow to in most situations as I can grab the rail and climb into the boat.

I just assumed it is a "no-no" to drop the anchor and tie to the stern of the boat.

Will get a chance to try it out in a few days time anyhow.

 

[pred02]

Just a little check in from Korcula. Loving the Ventura and the Adriatic. No problems with the boat, though someone snatched some of the ropes and other stuff we packed in along the way (have a feeling it was the locals), also cut out the bilge pump but we put the new one in.

Anyhow, here are a few photos, more will come the connection is not the greatest with the dongle here.

Here is the Ventura on a really cool cove off Peljesac.

A couple of questions (amateur) on trim tabs - still don't know how to use them the best. I guess I start with the engine down and the trim tabs (bow retracted). Then as I get on the plane I trim the engine up and the trim tabs bow down. Does that sound right?

Just trying to get the best performance out of the boat!

 

[MapisM]

A couple of questions (amateur) on trim tabs - still don't know how to use them the best. I guess I start with the engine down and the trim tabs (bow retracted). Then as I get on the plane I trim the engine up and the trim tabs bow down. Does that sound right?

You're cruising in some very nice places indeed, but your links don't work for some reason.
All I get is a message saying that... Either you do not have access to these photos, or they don't exist at this web address

Coming to your question, and without knowing (or remembering, anyway) which boat you're talking about, as a rule of thumb with outdrives you should always start with both drives and tabs completely down.
As soon as the boat gets on the plane, you raise the outdrive(s) first, bringing it (them) to the neutral position. Which means aligned with the keel - you should check in advance, visually, the correspondance between the neutral level and what the indicator shows.
By the time you're done with outdrive(s) regulation, it'll be time to raise also the tabs. Whose regulation is more tricky, because it depends on the boat speed and load, and on the sea conditions. In principle, the higher the speed, the higher also the tabs.
Tabs might also be useful to correct the boat listing in crosswind (just lower a bit the port/stbd tab to correct a listing to port/stbd respectively).

 

[pred02]

Hi,
It must be my Picassa settings, I've updated the sharing properties and the links so it should work now. I am off to Lastovo today, calm seas, will post more pictures and eventually videos when back.

Thanks

 

[Deleted User YDKXO]

A couple of questions (amateur) on trim tabs - still don't know how to use them the best. I guess I start with the engine down and the trim tabs (bow retracted). Then as I get on the plane I trim the engine up and the trim tabs bow down. Does that sound right?

Just trying to get the best performance out of the boat!

Nice pics, pred02 and nice boat too!. Yes, from a standstill, start with the engine fully down for max acceleration but as soon as you get on the plane, for max speed (and hence max fuel economy), the engine leg should be raised as high as it will go without the prop cavitating (maybe +2/+3?) but you will have to experiment to find the optimum position. Basically just move the engine up or down and watch the speed log or GPS speed at the same time. Be aware that this optimum position will change with different sea and load conditions
I wouldn't bother fiddling with the trim tabs as you already have the ability to alter the fore/aft pitch of the boat with the engine. Just leave the tabs up all the time and only use them to level the boat from side to side if the boat is leaning one way due to load or wind

 

[MapisM]

I wouldn't bother fiddling with the trim tabs as you already have the ability to alter the fore/aft pitch of the boat with the engine. Just leave the tabs up all the time and only use them to level the boat from side to side if the boat is leaning one way due to load or wind

Well, now that I've seen the OP boat, maybe he would be fine also following your suggestion above.
I suppose she shouldn't be that much sensible to trim & tabs, though I'll gladly stand corrected if pred02 will say otherwise.
Anyway, with planing boats, in principle exactly the opposite of what you're saying is true.
The prop thrust should rather be fine tuned according to the boat attitude, than used to correct it. It's also intuitive that the more neutral the thrust is, the better in terms of efficiency.
Otoh, correction of the angle of attack is exactly what tabs are meant for - the leaning adjustment is just a by-product.
Truth be told, your opinion is shared by many long-time users of boats with outdrives or outboards, but that makes it just more popular, not more correct...

 

[Deleted User YDKXO]

The prop thrust should rather be fine tuned according to the boat attitude, than used to correct it. It's also intuitive that the more neutral the thrust is, the better in terms of efficiency.
Otoh, correction of the angle of attack is exactly what tabs are meant for - the leaning adjustment is just a by-product.
Truth be told, your opinion is shared by many long-time users of boats with outdrives or outboards, but that makes it just more popular, not more correct...

I dont agree with that, Mapism. It is not intuitive at all that the more neutral the thrust, the better the efficiency (by neutral, I take it you mean that the hull and engine are prefectly aligned ie trim = 0 degrees). All planing boats ride bow up; they have to in order to present a planing surface to the water to generate lift. That means if the thrust of the propellor driving the boat is to be horizontal for max efficiency, the engine has to be trimmed upwards relative to the boat, hence the advice to trim out a couple of degrees.
As for tabs, its best in efficiency terms not to use them at all because when they are trimmed downwards, they cause extra drag. Thats why people say dont use them unless you have to which means only using them to correct lateral trim. Now thats not to say that some boats dont need them to get on the plane but thats a symptom of a poorly designed hull or overloading or lack of power

 

[MapisM]

Now thats not to say that some boats dont need them to get on the plane but thats a symptom of a poorly designed hull or overloading or lack of power

LOL, we obviously have a different concept of poorly designed hulls.
My lake toy needs tabs fully down (and they're BIG tabs!) to get on the plane, even when lightly loaded, and yet can cruise at 2 mpg.
And by "cruise" I mean 50mph, with an AoA between zero and 1 degree - practically unmeasurable.
Most boat of similar size/weight burn the same amount of fuel while cruising 40% slower.
I wish all the previous P boats I had were so poorly designed.

See, the whole subject is indeed tricky, because of course every boat is different, X dimension of the outdrive plays a major role, stepped hulls are different from non-stepped, and so forth.
But the principle remains the same: you control the boat AoA with tabs, and adjust the leg consistently. Not the other way round.
The only case in which you might wish to raise the leg "as high as it will go without the prop cavitating", and fully raise the tabs, is when trying to squeeze the last knot out of a speedboat running at WOT, because by forcing a higher AoA you can reduce the wet surface, and depending on the speed this can more than compensate the efficiency loss of a drive set above its neutral position.

Btw, nope, by neutral I meant horizontal.
I understand the confusion though. With hulls whose AoA is 5 degrees (or whatever), I agree that the drive should be trimmed out accordingly.
But not "as high as possible", anyway: if the outdrive/outboard is installed with the plain vanilla X dimension (cavitation plate level with the keel), it takes a helluva trim to make them cavitate, well above horizontal thrust.
The most likely effect is that the boat will porpoise, hence requiring more tabs. Not a good idea.

 

[Deleted User YDKXO]

Btw, nope, by neutral I meant horizontal.
I understand the confusion though. With hulls whose AoA is 5 degrees (or whatever), I agree that the drive should be trimmed out accordingly.
But not "as high as possible", anyway: if the outdrive/outboard is installed with the plain vanilla X dimension (cavitation plate level with the keel), it takes a helluva trim to make them cavitate, well above horizontal thrust.
The most likely effect is that the boat will porpoise, hence requiring more tabs. Not a good idea.

Were going to have to agree to disagree on this, Mapism. For me, trim tabs are only to be used when necessary and to some extent make up for the deficiency of a hull design. Btw I did qualify my statement about raising the drive as high as possible in order to find the max speed. Quite obviously, if the boat starts porpoising or starts exhibiting any other unwelcome characteristics, it is unlikely to be achieving its max speed

 

[MapisM]

Were going to have to agree to disagree on this, Mapism.

Fairenuff. You're welcome to come and try first hand why a proper planing hull can actually be driven by trim tabs.
I suspect that your comments are based on boats where tabs must be used because without them reaching the bow actually means climbing, rather than walking...
That's a very common problem with many P boats, also modern ones, which are not designed to optimize the hull efficiency and weight distribution, but rather to give more internal space, be able to store big and heavy toys astern, etc.
Forget them. As Sonny Levy used to put it, trim tabs are meant to ADAPT the hull attitude (to different conditions: sea, speed, etc.), not to CORRECT it!

 

[pred02]

A couple of more photos from our trip in Croatia.

Watching the sunset off from a mooring restaurant in Loviste. Very nice people there were helpful when we got thrown on some lines and had to handle our way around. We then drove back to Korcula with the sunset in the background.

Cove off of the back of Korcula (facing Lastovo and Italy). I think it's Orlandusa though it's one of the first coves around.

The Whaler in the cove.

Plocica Lighthouse near Lastovo

The trims are better but still only getting around 2-2.5 mpg I expected the economy to be around 3mpg but I guess it depends on the load and the number of people on the boat.

Will post more adventures.