Bildiğim kadarıyla araç güvertesi dolu.

Literally, it is something like to the extent that I know or by the amount I know.

In natural English, it means:

• as far as I know
• to the best of my knowledge

It is a very common Turkish expression for giving information without sounding 100% certain.

Because Turkish is not saying I know as a full verb here. Instead, it uses a participle / verbal adjective form meaning what I know or that I know.

So:

• biliyorum = I know
• bildiğim = what I know / that I know

In Bildiğim kadarıyla, Turkish needs the second type, because the phrase is built around the extent of what I know, not a full independent clause.

It comes from the verb bilmek = to know.

Breakdown:

• bil- = know
• -dik / -dık / -duk / -dük = a suffix that turns a verb into something like what/that ...
• -im = my

So the underlying form is roughly:

• bil-dik-im = what I know / that I know

Because of sound changes, k softens to ğ here:

• bildiğim

So bildiğim literally means what I know.

This is part of a common pattern.

• kadar = amount, extent, as much as
• kadarı = its amount / its extent
• kadarıyla = by its extent / to its extent

In the full phrase:

• bildiğim kadarıyla = to the extent of what I know = as far as I know

You do not need to analyze kadarıyla every time in conversation. It is best learned as part of the whole expression bildiğim kadarıyla.

Because it works like a sentence adverbial or framing expression, similar to English as far as I know.

It sets the speaker’s level of certainty before the main statement:

• Bildiğim kadarıyla araç güvertesi dolu.

This is very natural in Turkish. It is basically saying:

• As far as I know, the vehicle deck is full.

It is a noun compound.

• araç = vehicle
• güverte = deck
• güvertesi = its deck / deck of

So:

• araç güvertesi = vehicle deck / car deck

This is the normal Turkish way to make many compound nouns. The first noun often stays bare, and the second noun takes a possessive-looking ending.

Other similar examples:

• otobüs durağı = bus stop
• yatak odası = bedroom
• uçak bileti = plane ticket

Because in this kind of Turkish noun compound, the second noun usually takes the 3rd person possessive suffix.

So:

• güverte = deck
• güvertesi = deck-of / its deck

Since güverte ends in a vowel, Turkish adds a buffer -s- before the suffix:

• güverte + si → güvertesi

This does not always mean literal possession in the English sense. In compounds, it is just standard Turkish structure.

These mean different things.

• araç güvertesi = vehicle deck
  A general type of deck, a deck for vehicles

• aracın güvertesi = the vehicle’s deck
  The deck belonging to a specific vehicle

In your sentence, araç güvertesi means the deck used for vehicles, such as on a ferry. So the compound form is the right one.

Because Turkish often leaves out the present-tense to be in the 3rd person.

So:

• araç güvertesi dolu = the vehicle deck is full

This is completely normal. Turkish does this with noun and adjective predicates all the time:

• Hava güzel. = The weather is nice.
• O mutlu. = She/He is happy.
• Kapı açık. = The door is open.

So dolu is the predicate, and the meaning is is understood.

Yes. Dolu means full.

In this sentence, it functions as a predicate adjective:

• araç güvertesi dolu = the vehicle deck is full

Depending on context, dolu can mean:

• physically full
• occupied
• packed

Here it means there is no more room on the vehicle deck.

It sounds cautious and limited, not fully certain.

It tells the listener:

• This is what I understand
• I may not have the very latest or complete information
• Don’t treat this as an absolute guarantee

So it is softer than just saying:

• Araç güvertesi dolu. = The vehicle deck is full.

With Bildiğim kadarıyla, the speaker is hedging a little.

Yes, you can.

• Bildiğim kadarıyla = as far as I know
• Benim bildiğim kadarıyla = as far as I know

Adding benim gives extra emphasis, often for contrast:

• Benim bildiğim kadarıyla araç güvertesi dolu.
• As far as I know, the vehicle deck is full.

Usually, though, benim is unnecessary unless you want emphasis.

Yes, but the original order is very natural.

Common version:

• Bildiğim kadarıyla araç güvertesi dolu.

You could also hear:

• Araç güvertesi, bildiğim kadarıyla, dolu.

That can sound a bit more marked or conversational. Turkish word order is flexible, but the normal pattern still tends to put the main predicate near the end, so dolu naturally stays at the end.

Because in Turkish compounds, the first noun is often left in a basic singular form even when English would sound plural.

So:

• araç güvertesi literally looks like vehicle deck
• but in English it may naturally mean vehicle deck or deck for vehicles

This is very common in Turkish. The first noun in a compound often behaves more like a category label than a countable singular noun.